This is the build i use when i play skarner it helps me use skarner a lot.
I use this build in top lane with someone to help at the lower levels.
In addition to this i would recommend getting the blue buff at level 3 so you can use all you ablitys.
when you unlock skarners ulti i would recommend it for dragging enemys into your turrets at lower level and at higher levels isolating a enemy champ and then dragging them to your team.

pros:
-true hybrid allowing for damage, attack speed, Armour, health. mana, life steal making you even harder to bring down
cons:
-slow making it hard to escape enemy
(unless you use the crystalline exoskeleton to get the speed boost)
-low magic Resistance (if versing high magic damage enemy's this build will not be as effective)