Hi guys this is my first guide so bare with me :).
First time I played Skarner I had no idea what to do with him so I checked out the Champion Spotlight and wow another jungler I dont want to play xD Ive noticed hes good at killing jungle creeps but he still levels rather slowly (or it might just be me) I play various junglers from Yi, Udyr, Warwick and Tryndamere and Skarner is well off the pace.

So here it is, my laning build for Skarner.
Ive focused on building him as a Hybrid AD/AP melee DPS, in the item section of this guide the CORE is the items you 100% need to be a good skarner the others are up to you, if your dying alot change them Ive written the items that work for me with my play style :).

Before you read this section and in fact the rest of this guide let me just say Skarner is not Overpowered in anyway it all depends how you play him, you wont dive a team and pentakill them instantly so dont expect to.

PROS:

Has alot of nice aoe damage
Has a heal that he can farm very quickly with E and Q
Is a great chaser with W and Q combo
Benefits from AP and AD very well
Can interrupt ultis such as Katarina, Nunu and Warwick with his ulti
Can Rofl pull noobs into towers with ulti

CONS:

Doesnt have a low Cd hard CC
When you pop your ulti get ready to run because you will be focused
Can be very squishy early game
Flashing while you have your ulti on someone doesnt work

For Runes I use 9xArP Marks 9xAS Seals, 9xFlat CdR Glyphs and 3xFlat AP Quints.
This set up gives you a little bit of AP at level 1 meaning you can get your Sapphire crystal giving you more damage and harras. It gives you ArP and AS for your auto attacks which teams up nicely with Trinity Force and your passive which lowers your Cds when you auto attack. CdR kind of speaks for its self, the lower your Cds the more spam you can throw out.

If your having trouble staying alive early game Id suggest switching out the AP Quints for flat HP.

For masteries I take a pretty standard AP caster set up (9/0/21) taking cripple and archaic knowledge in Offense and taking Blink of an eye, Presence of the master and 2 points in utility mastery. These masteries give you a nice mix of damage and sustainability though it does sacrifice a little on the tankability side that shouldnt matter if your playing him right.

For items Ive gone for a mix of AP AD AS and CdR items the core items for this build are as followsreasons for these I shall explain. Trinity force there is nothing you can dislike about this item the stats are all good some crit some hp some damage its got it all.... and one of the best item passives in game when you cast an ability your next attack deals an extra 150% of your base attack damage ONTOP of your normal attack so its amazing. Hextech is such a nice item for skarner for one the use on it is a nice extra bit of burst and the damage ap lifesteal and spell vamp make it amazing when spamming your Q and chasing them down. Guinsoos, now I wasnt sure wether to put this into CORE but I decided I would because its such a cheap item and when you spamming your Q its up about 80% of the time the other 20% is you having to either run at or away from you enemies. I will say this now any Item with a nice amount of attackspeed and either AP or AD is amazing for skarner because his passive makes his AS work similar to CdR.
NOW BOOTS I dont like builds that tell you what boots to get because it all depends on your enemy team so Ill leave the decision up to you, I generally takefor the attackspeed but its up to you.

Optional Items:
This section depends on the enemy set up.

If your enemies are main AD champions you can take items such asbecause burning your target while you have them locked in your ulti is amazing :) the armour and HP is nice too.the debuff is nice but the main thing is the armour and the CdR also a very nice item for countering AD teams.

If you are coming up against a hard AP nuke teamwould be a god send along with others such asand
If your enemies are failing and your clearing up Id suggest picking upAS CdR and AP all win for skarner. Either takeorbecause everyone loves mana and damage based on your mana and/or ripping through armour at a stupidly high speed :).

For summoner spells its really up to you depending on your play style, I tend harras from a distance with my E to get them down abit then I hit another E start to charge pop my W then attack them while spamming my Q if they start to back off before I can get into range for my slow I either exhaust them move in and spam or flash and do the same.

I dont really like guides that tell you exactly what summoners to use, I mean certain ones are out of the question eg: Revive, Smite(unless your jungling of course) and Rally but if you like killing luckers with Ignite then go for it.

At level 1 buy aand 2xhead to your lane (if you can get into the shrubs closest to your enemy tower) and wait until your enemies show up try and harras them with your E while also hitting creeps with it so you can heal yourself with auto attacks, LAST HIT as much as you can use your E and Q to do it if you want just make sure you LAST HIT. When you have enough gold Recall and buyand, head back to lane and farm some more. If you get the chance to pick up First Blood try to hit Q as early as possible to get them slowed, then follow up with an E and Q combo you may have to pop exhaust and/or flash to keep with them DO NOT DIVE TOWERS UNLESS YOU ARE GOING TO KILL THEM FIRST!

Mid Game is where you can really start to shine as skarner you should have or be close to having, whichever boots you decided to take and be working on yourlook around the map for where you think a teamfight will start, wait for the tank or someone to initiate, dive in and grab one of their carries or a support (something that needs to be locked down) with your ulti, pop W run toward your team or your tower while spamming Q and E and congrats you should have atleast killed 1, 2 or scored an ace.

Late Game you have to really be focused in team fights on keeping the most disruptive players off of you carries and squishies such as Warwick and Katarina champions that can lock down or really deal alot of damage to your team, to do this you need to wait for them to pop their ulti then use your ulti on them pull them into the firing line of your carries, if you pull this off and win the teamfight its time to take baron or push a tower. Make sure when you move into the tower pop your W to give you a boost in attack speed and a shield that can soak abit of damage for you make sure you use your Q on cooldown when pushing a tower to make your Trinity proc giving you alot more damage on the tower.
At this stage you should have finished your CORE build and be working on the situational items.

Ive found since I started playing Skarner Ive really started to work better as a team player by making the sacrifice of diving in to stop their carries with my ulti, I die, they die and most of their team die.

Skarner isnt OVERPOWERED like pretty much every champion Riot have released in the last 6 months (with the exception of Yorick pre patch of course)

One final word, This is my first attempt at a build on mobafire any constructive criticism will be taken onboard and I will try to keep this up to date with patches and any suggestions you feel would benefit it (You will be credited for your input in a new section to this build called "With Thanks To")

Thank you and goodnight :)