Okay so this is my first guide (I am INCREDIBLY new to this) and is something I have been trying out. Thought I would make a quick guide on the basics. I know Teemo is not normally used for support these days but I feel he can actually be a good pick as support. The key to this guide is to show you a build to use, and to help explain how to use Teemo as an effective support that can also be a semi AP carry in late game. I will try and update this as much as needed. Also, I am sure my grammar is pretty horrid, its not a lack of education more of a lack of care usually on my part.

Pros
- Good harass with his blind
- Good escape ability
- Good ability to help whiddle health with
- FREE WARDS THAT DO DAMAGE!!
- Epic global taunt

Cons
- Not a huge amount on range
- Super Squishy
- Can KS if played super aggressive
- CDR reliant for the shrooms
- Not normally played as support

The items I have chosen to use on Teemo are semi support and semi ap carry. The whole purpose is in the early game you are full on support, once you hit lvl 6 you get your mushrooms to use as wards. You should still buy wards, and you should encourage your team to do so as well. I like to try and get philo stone and kages as soon as I can to get that yummy yummy gold coming in. You should play like any other support and try not to get cs, so these items are very much needed. The boots of lucidity I choose as the cdr from them helps get your shrooms out faster. Shurelya's is a must for almost every support, not to mention the health and mana regen it provides as well as the cdr are really useful, and lets not forget the on use ability, very much handy. After that I get shard of true ice, an item with a great on use, great passive gold, and it provides ap, as well as giving you and all your allies more mana regen. After that I focus on liandrry's, this is where you are going to see a huge jump in your ap. This will also provide a useful dot with your shrooms. Always handy to knock some health down, especially if they run into trying to initiate a team fight. After this I go for Twin Shadows as it provides AP and MR. The on use ability is also really hand, especially if they have oracles and are clearing you shrooms/wards out. Finally we work towards getting runic bulwark, this item is pretty much a must on most supports. If someone else builds one I still suggest getting it. Another option is to get Locket of the Iron Solari, provides armor and more cdr as well as has a great on use ability.

The goal of this Teemo is to play a support role primarily. This being the case you should get your Q maxed first as its a great harassing tool. You should max this ability first. Second you will get the popular poison, his E. This is good for whiddling down some HP on anyone you hit, helps get our carry a kill, and since you wont have a ton of AP early on nor much attack speed you shouldn't get the kills. I max this second. Finally your W. This ability provides great movement speed, early levels it provides enough that you only need one point in it. I max this last. And fourth, your R, this is your ultimate, this is going to be something you will be trying to focus on using as much as you can. Abuse this all the time, you will be placing mushrooms everywhere. This gives free mini wards that also explode and do damage as well as slow the enemy that hit it and all those next to the explosion.

So I know this will probably not be a popular thing, but I also know it can work. I really believe he can be a good viable support. I really hope people try this. If you have anything to add please feel free, if you have anything negative to say (unless its constructive) then please take it elsewhere, you don't have to try it so just move on.