A Laning Ap Skarner can dominate ap/ad carries as well as tanks, zoning out enemy champions with ease. Skarner is not able to jungle fast compared to other junglers(ww for example) and I find ad Skarner to have little power during laning phase. Laening towards Ap more than ad allows Skarner to harass and zone enemies more than regular hybrid builds would.

*note - this guide is not complete and will be updated soon*

Pros

Great harassment early game
Able to dish large amounts of damage
Stay in lane longer with heal from fracture
Holds up exceptionally well solo lane
The center of any team fights
Faster farming than jungling(during solo-lane)

Cons

extremely expensive build(note Kage's lucky pick)
low mana in the beginning
Slow attack speeed
not as durable as tank Skarners

boots of speed - A great advantage to Skarner is his fast movement speed. getting this will help you get on your enemies and the ability to escape. This should be built intoMercury Treads orsorcerer's shoes
Kage's lucky pick - This build is expensive and takes up a lot of gold, getting this item helps pay for all of your items and gives you a decent 25 Ap boost
sheen - giving you both Ap and mana, this item will work wonders with Skarner early game. the extra damage its passive is a bonus that you can't ignore
Hextech Gunblade - This item is a must. Giving you Ap, Damage, lifesteal, and spellvamp, whats not to like!
Trinity Force - Scarner becomes godlike with this item, giving him everything he needs to dominate teamfihgts, ganks and whatever you run into. the movement speed boost is also very nice
[*]Guinsoo's Rageblade - giving you ap, damage and attack speed, rageblade works really well with Skarner

I chose to getFracture first and maxing it out by level 9, increasing your harassment abilities in lane. the next skill you should max out is yourexoskeleton while getting points into yourImapale as soon as possible. Your first skill is not first priority because E with a well timed Impale will do much more damage.

*edit you can choose to max outexoskeleton orcrystal slash next, it depends on how you play Skarner*

Ignite - enables you to get kills when enemies would usually run away with low health. the extra 10 Ap when this spell is on Cd is also neat
Ghost - Skarner is speedy as it is, and ghost will both serve as an escape option and a good ganking spell

Optional spells
Exhaust - a good option to take, I prefer ghost over Exhaust simply because it is a good escape option
Flash - Flash can be used to land your ulti on any enemy champions that are too far away to chase down with ghost
Clarity - Skarner has problems with mana early on and clarity can help you spam your E more often

Beginning Phase
First off, buy boots and 3 health potions to start off. Put your first skill point into Fracture(E). You should be using E to harass the other team because you do not want to get up close this early into the game. Line up your shots to hit both minions and enemy champions. It is likely you will get poked by the other team and doing so will give yourself a chance to heal by auto-attacking minions. When you get your ultimate always look for a chance to nab champions away from their turret or into yours. It will be easier if laning with anyone with cc as they can help you trap and kill any enemies that are turret-hugging

Middle Phase
This IS where the fun begins. The one MOST important thing you need to know is that when Skarner is in a team fight, your job drag out the Dps carry first. Skarner is able to keep Dps champions such (Master Yi, Tryndamere etc.) at bay and away from your teammates. First priority goes to Dps champions but if they are not around, your job changes to dragging Ap casters and squishes TO your team. Skarner is great at going through tanks and taking squishes into the heat of the battle.

End Phase
*IN PRogress