this guide is a GUIDE. If you find it isn't working for you take a moment and evaluate why. You may find that a simple tweak to this build is all you need. after all i main skarner and i rarely follow this build to the letter. its more of a foundation for a variety of builds to help fit most situations.

Pros
locks enemy champs down well
pretty good damage
pretty survivable in 1v1s
can occasionally tear people up 2v1
Solid in team fights due to AoE spam
Fast. End of the game you can drop w for 500+ movement speed

Cons
VERY MANA DEPENDENT early game. mid-late game not noticeably.
laning opposite to a good ranged character can harass you to the point of starvation.

If you don't know why I picked those masteries, then i will explain briefly. I goal with skarner is to lock down your opponent and then beat them into the ground, and to do this you want to be able to spam his q ability as frequently as possible. So for masteries you want damage and cool-down with a some mana regen mixed in there as well.

Before i describe each skill and tell you why i love it and why you should love it let me take a moment to note a simple alteration that can be made to this build. Look at the skill progression. that fits most situations; however, sometimes i level the w and e skill straight through one at a time after level 8. Sometimes i don't. Also the skill choice at level 7 is one of those as needed things. if you find you need the w, get the w if you think the e skill would be better, get the e. remember this guide is a foundation for a variety of builds.

Skarner's passive is the backbone of this build. every auto-attack you dish out recharges ALL of your skills (that includes ulty, but not summoner SPELLs). The way this works is each minion/monster hit recharges for .5 seconds, each champ hit recharges for 1 whole second. Note, this does not have one of those "this can only happen x many times in x amount of time" thus if you rolled a diff build with all attack speed you could recharge your skills for up to 3 seconds, per second of combat. but for our purposes it will not get that crazy.

Skarner's q is going to be your go to skill. it deals damage to a small area and slows, if it strikes a target a second time within 5 seconds it basically double the damage output. So this is the skill you want to spam for pretty good damage and to keep the opponent where you can eat them. Thus you max this as soon as you can. after you get all your other skills to level 1, of course.

Skarner's w is as much a life saver as it can be a life taker. So firstly you need to understand how this skill can save you. its a shield and speed buff with a pretty solid duration. 'nuff said. Now how this skill can take a life, is a bit different. this skill not only buffs movement speed, but also buffs Skarner's attack speed. So this skill when its not helping you run from a fight with your tail between your legs also helps you charge into a fight, and once in the fight you attack faster. couple the attack speed buff with Skarner's passive and your skills are recharging that much faster.

Skarner's e is a nice little tool when used correctly. First its a straight line skill shot, so aim for the most hits possible to mark multiple minions and in team fights multiple champs. Now note, it is ranged. so it works great to just harass melee champs. its also fun to use on players who don't know skarner well as they simply don't see it coming, or misjudge your range. Ok where this skill gets good. Skarner can consume the marks for a small bit of healing. this healing reduces each time a mark is consumed. most say this is garbage healing, but if you tag a bunch of minions then drop q on all of them, its can be a nice helping of healing. Also, when you get good and can instantly judge the strength of this skill it makes a good finisher for those who think they've gotten away.

The Ult/ R skill. This is going to be your baby. trust me. Suppression for two seconds, the ability to tug them around, and a little damage on the side. Yea this skill kicks ***. I've done many things with it, but genereally i use it to grab them if they are running or engaging. What popping ult as your first skill? yea basically. Firstly Skarner's ult early on has a decent cooldown, but late game coupled with his passive you can probably pop it every engagement you find yourself in. So yea use it. Second, it suppresses them and you can pull them away from whatever they were going for (or in the he case that you were the target you pull them further from safety :towers, their teammates, ect) the thing to realize about this skill is while they are suppressed you can drop your q on them. Generally you can drop them plenty of health before they can really drop you any at which point they run, you chase, you eat.

So the thing to realize with this build is that if you make it through all of the items (which believe it or not i often do) you've enhanced most every aspect of Skarner's stats. AD, AP, Attack speed, cooldown, mana regen, armor, magic resist, and movement speed. That being said, this build can go in any order after you get the chalice of harmony. However, don't take that and go "okay, lets do it this way just because." Why? you'll die, thats why. These items are only to be switched on an as needed basis. example. You've just gotten the chalice and you've been died more then two times. unless you feel comfortable with that, you should probably get the glacial shroud before the zeal. heck i've even gotten frozen heart super early (although i don't advise it) So the thing to take away from this is that Zeal--> Phantom Dancer and the hextech revolver are the core items to this build. For the noobs, the basic way to judge how to approach the items here is if you need defense get the shroud before you move Zeal->revolver->dancer. if you are doing good the follow the build. Once you get the Phantom Dancer if you feel under-powered go ahead and get the gunblade, sheen/lichbane.

Here's a quick run down of the usefulness of each item:
Ninja tabi: Speed + armor + dodge
Chalice: MR, mana regen and the passive 1% mana regen for each % man depleted.
Zeal/ Phantom dancer: AS, Movement speed, and critical strike.
Revolver/gunblade: Vampirism and AP/AD boost.
Sheen/Lich bane: AS, AP movement speed, and the passive attack bonus when skill weaving.
Glacial Shroud/ Frozen Heart: CD, Armor, Mana plus frozen heart slows nearby enemy champs.

So the Basic idea with the item is speed, mana, AP and CD.

The basic run down on how to play this build and this champ. first realize skarner has plenty of AoE. granted most of his AoE is short, it still allows for plenty of farming. early game drop q often on minions and go ahead and start getting those items.Next, when you find yourself in combat (against another champ) its good to drop all of this skills. usually like this ult->q->w->q->e->q. Notice a trend? Yea you want to drop q as much as possible, it slows and if you can keep hitting them does fantastic damage. now if your fight takes longer (which it is very likely against tanky-er champs) you want to prioritize your ult and q followed by w and e. obviously your ult is an opener. That's about it, most everything is explained in the above sections. The thing to understand about skarner and really any champ, is they can be played different ways and as such it takes practice to identify when certain situations arise how best to deal with them. This guide especially takes practice to get reallllllll intimate with skarner and know his weaknesses as well as his strengths. Also this build can jungle well after the hextexh revolver (if you're good you may not need the revolver), if you grab a buff, skarner can usually get some good ganks.