Spoiler: This guide is not going to be super in-depth or anything. I'll cover a few basics about Teemo, but he's an easy enough champion to get the hang of that I'm going to focus primarily on the build I use.

Second spoiler: This is the best Teemo build ever designed by a mortal man and is therefore immaculate and must not be altered on pain of death... JK! In fact, if anyone reading this (all two of you *sigh*) has some bomb-a55 ideas they want to share, please do. While this is the best combo of items and runes that I have personally found useful, I am all ears if any dudes have suggestions.

Third and Final spoiler: I almost always play bottom lane Teemo, so I have little to no experience with this build while playing solo mid or top. That being said, I cannot be held responsible if your Teemo gets butt-raped when you use this build while solo laning.

With these things in mind, read on friends!

Greater Glyph of Scaling Ability Power: If you're like me, your pvp games on LoL last an average of two days each, so you'll be reaching level 18 one way or another. This makes these Glyphs ultimately more useful in the long run than Greater Glyph of Ability Power, although I can still understand if you would prefer them, since they do give you a slight lead in AP early game.

Greater Mark of Magic Penetration: Unless if your enemies are packing some Magic Resist runes, having Magic Penetration from the get-go means you should be dealing almost true damage for the first few levels. This means it shouldn't be uncommon for your pesky Toxic Shot's poison to nom up any remaining Health on a fleeing champion you just lit up after coming out of Camoflague.

Greater Seal of Vitality: Since I have absolutely no health items in this build and Teemo can sometimes be considered squishy to a near suicidal degree, having 175 more health by level 18 can be the difference between "Still alive and poisoning *****es" and "Here lies a bloody pile of fur that once ressembled Teemo" in team fights. If you decide that having magic resist or armor would be more useful for your seals, go ahead... you can be DEAD WRONG if you want. I kid, I kid *chortle chortle laugh laugh*... or am I?

Greater Quintessence of Ability Power: Gives you a solid 15 AP to start off with, which makes me feel a little bit less nooby when I start off my items with Boots of Speed and pots instead of a Doran's Ring like all the MLG people seem to do these days.

Pretty standard 21/0/9 set-up with an emphasis towards AP. As far as the utility points go, just do whatever you feel you would benefit most from as long as you ultimately get Runic Affinity .
The reasoning for this is Teemo can be a really good jungler by level 6 once he has Noxious Trap (pop a mushroom in front of the Red Buff's walking path, Camoflague, then light him up until he reaches you. Then pop Blinding Dart and auto-attack that sona***** to oblivion).

NOTE: Don't be a furry ***** and nab every buff ever unless you first get the "KKZ" ("Okay" for you English speakers) from your teammates/jungler.
Also, make sure it's safe before you begin fighting your buff. Try to ward any brushes or paths leading to you with your Noxious Traps.
Nothing sucks more than almost nabbing that Golem only to have the opposing team's jungler catch you with your cute little shorts around your fluffy ankles. What oftentimes occurs from such unpleasant surprises will go unspoken due to its dark and sad nature.

Exhaust: Teemo's best friend. Can make an enemy burn a Flash only to die a horrible death from poison, or even give you the upper hand in a 1v1 fight with an AD Carry (NOTE: If such a fight does occur, just be ready to die with him. Cuz you hella squishy, man). You couple this spell with 5 ranks in Move Quick and you can chase down just about anyone as well.
THIS IS A MUST-HAVE ON TEEMO. The second Summoner Spell can be pretty much whatever, really. Imma stuff a few suggestions for that one down your throat anyway, cuz I'm a jerk :D

Mr. Bigglesworth's Top 4 Other Spells

Flash: When just being able to run like the dickens with Move Quick isn't enough to get you out of a pickle, blinking through a wall might be. One of the most versatile spells in your arsenal fo sho.

Teleport: This can turn Teemo into a ganking machine at later levels, because he can Teleport onto his Noxious Trap mushrooms. Super fun when it works, but because of the limited sight warding of your shrooms you can sometimes find yourself stuck in some not-so-fun situations.
Only use Teleport if you deem the occasional high-profile gank worth the risk of Teleporting into a shrubbery with a sexually-frustrated Alistar in it.

Heal: Since poor little Teemo is defensively weak against practically everything when his Move Quick and Blinding Dart are on cooldown, popping a much needed Heal here and there can boost his lane sustaining abilities vastly.
I find that, unless your foes are getting pretty darn fed, Heal isn't really too badly needed as long as you play Teemo like me: A cowardly vagina that spews as many toxins as possible at unsuspecting victims before booking it to the loving bosom of the nearest friendly turret.

Ignite: A very good offensive spell that can spell certain doom for a poisoned opponent, but I'm a bit leery towards having both my Spells geared towards attacking. If you aren't bothered by this, however, give it a shot.

I guess you could get Ghost on Teemo as well, but considering that your speed is already pretty high and Ghost won't do you any good once you're Exhausted or slowed, I would stick to Flash or Teleport.

(Q) Blinding Dart I like to put my starting point into this because it can really help out your laning partner (or yourself, if you're soloing) against any early-on problems with AD champions thanks to the blinding effect. Max this baby out by level 13, cuz it will be your main damage against champions and super-valuable in team fights.

(W) Move Quick: I don't put a point into this until level 4 because, while useful as an escape mechanism, I find it the least important of Teemo's skills. Rank it up last at 18.

(E) Toxic Shot: Teemo's bread and butter. This makes farming a breeze and laning champions wary of staying in range too long. Teemo's poison effects are powerful enough by rank 5 to straight up kill squishy competitors, and easily pick off any bulkier enemies running away with low health. I always get this to rank 5 by level 9.

(R) Noxious Trap: Poisonous, stealthed, and like a free sight ward in some ways. By far the most defensive and useful of Teemo's goodies. Make sure to spam them as much as humanly possible, and in as many bushes and important places (i.e. Dragon, Baron, Buffs, etc.) as you can!

Boots, 3 Health Potions: Great for lane control and sustaining, and makes second tier boots affordable within minutes.
Next Best Thing: Doran's Ring Gimme dat Health/AP, son!

1. Sorcerer's Shoes: That 20 Magic Penetration will give Teemo teeth early on, and almost completely negate the Magic Resist boosts of someone with Mercury's Treads.
Next Best Thing: Berserker's Greaves A decent Attack Speed modifier for early game.

2. Nashor's Tooth: Everything here is essential to a successful ninja squirrel attack. Cooldown Reduction and high Mana Regen means more Blinding Darts and Noxious Traps, while the AP means those things do more damage as well. The giant Attack Speed bonus makes sure your enemies' poison subscriptions are always to date, while that AP makes sure it stings more. Great item that is practically required on Teemo.
Next Best Thing: NONE. U HEAR ME?! NONE!!! O.o

3. Malady: Ability Power and Attack Speed is always welcome on my Teemo (did you not see the title of this guide?), but those things aren't the main appeal of Malady. The thing that makes Malady awesome is that the 20 bonus magic damage stacks directly onto Toxic Shot, and after just 4 basic attacks enemies will be forced to reckon with your poison stack with 24 less Magic Resist (with your runes and boots, that is about 52 Magic Resist you just ate! That is almost exactly proportional to an Abyssal Mask worth of protection you tore through).
Next Best Thing: Frozen Mallet This item is great if you are really feeling vulnerable with Teemo's squishiness and are getting ganked like a mofo. Having a hugely annoying and constant slow isn't bad either.

4. Deathfire Grasp: Some healthy AP as well as a wicked active that can be devastating when used to initiate a gank. Plus you'll be maxing out the Cooldown Reduction cap at 40%, meaning if the map isn't just completely swarming with mushrooms now you're doing it wrong.
Next Best Thing: Abyssal Mask AP, Magic Resist, and even more Penetration (insert immature giggle here) all in evil staff thingy. What's not to like?

5. Wit's End: Getting some Magic Resist by this time would be a good idea, considering you should be having team scuffles just about every damn minute (or whenever it's least convenient for you and your squishy brethren) in this stage of the game. If you have been getting all of the first items on this list, you will now be just on the brink of hitting the Attack Speed cap (2.5 attacks per second... lol), as well as 62 bonus magic damage from Wit's End and Malady combined. That is 107 bonus magic damage with Toxic Shot maxed out, even before AP is factored in! Add that to the fact that literally every attack you deal will cause dudes to lose Magic Resist while you gain some means you can squash individual mages. YAY.
Next Best Thing: Madred's Bloodrazor If you got Abyssal Mask earlier, then get this. You won't quite have the same shroom-spammage capacity since you don't have Deathfire Grasp, but the fact that you will be knocking off 4% of a foe's max health every hit is pretty impressive. Great for mopping up the resistance in team battles, but just remember that this 4% isn't immune to Magic Resist before you start a wild goose chase with a running champion.

6. Zhonya's Hourglass: 100 AP equals 14 more poison damage every second and 80 more points for you precious Noxious Traps. Not bad. Throw on some armor for survivability and an active that will save your butt and burn ultimates like nothing else and your Killer Teemo is complete! Happyface.
Next Best Thing: Rabadon's Deathcap If you're keeping the enemy AD dealers defanged with Blinding Dart to the point of them not even posing a threat, and/or don't see the end to this game in the immediate future (God rest your soul, you must be into your second week of playing to have had this much gold and still not see the end), get Rabadon's Deathcap to finally get your GG. When you have this much AP and speed with Teemo as you do now, the only way I can see you losing is if all your teammates were suddenly replaced with deformed babies and all the enemy champions turned into overfed Master Yi's. Seriously. Only way.

NOTE: I added a second build with all the Next Best Thing items, if u prefer that build.

Killer Teemo Build: 13.6k Gold

Next Best Thing Build: 17.4 Gold

Daaaamn, datta lotta monay, son! Add on the fact that Next Best Thing's build doesn't have a Kage's Lucky Pick and you are going to need a ridiculously long and lucritive game to complete that item build. Just things to in mind, folks.

Well, I think that about covers it! If you have any questions, comments, or mindless troll hate to give me, please leave a little something something under the discussion thingamadoodle. Thanks for putting up with my criminally bad sense of humor and generally atrocious writing, and leave me a vote if ya feel like it ;)

This is Mr. Bigglesworth, signing off to go do crack cocaine while listening to ****ty dubstep.

DISCLAIMER: Mr. Bigglesworth does not condone the use of recreational fun- er, I mean drugs. Or ****ty dubstep for that matter.