Skarner is a hero that really fits for jungling.Have seen many good skarner laning but his true potential is showing off only by jungling and ganging.Skarner is so frightening when is ganging.W+R...what else do u want?

For runes i use

armor penetration marks,armor seals,magic ressist glyphs,and armor penetration quintessencesThis rune build helps me at jungling while i dont take much damage from the minions and armor pen is there for ganging doing nice damage

I go offensive using 24 in offense and 6 in defence.You can go more defensive too.Works really well but i prefer the offensive tree for the extra ganging damage

Take 1 lvl crystal slash,then Crystalline Exoskeleton and crystal slash again following with fracture for the hp regain.The rest is easy.Ulti and then try to fully lvl up crystal slash together with exoskeleton

Start at the blue buff.With this build u can do it even without pull but you'll be pretty much low on health so ask your teammates to pull for you.

Blue buff<Wolves<liches<then golems and again wolves etc.It would be wise to look for a gang at lvl 4

Start with a Cloths Armor and 4 Health Pots.When u kill the neutrals at the order above u should have enough g for Madreds Razors.If not buy a boot together with some health pots and try to gang.
I prefer Mercury Treads over Berserker Graves but this is up to you.If they dont have cc then u can go Graves.Then i would suggest to build your Madreds Razors into a Wriggl's Lantern if u want to go a bit more tank or a Madreds Bloodrazor if you want to be more aggresive.I go Madreds when we have no other dps,or when our dps doesnt have a madreds when the enemy team has 1 or 2 tank champs.I go Wriggle's when i really need that extra armor.Usually because they have 3 dps.
Either way i would suggest to build Sheen before buying Madreds or Wriggle's for the extra damage.
After u have the boots of your desire,sheen and Wriggle's or Madreds finish Trinity Force.
In my opinion it's his core item.HEALTH MOVEMENT SPEED DAMAGE are all there to buff him up together with the extra damage that triggers.If they have a tanky team or at least many hight health champs buy a Black leaver to reduce their amor and then hit them really hard with your nice damge from Trinity.If they dont have or if you dont like Black leaver u can buy a Bloodthirster .Together with Wriggle's makes you quite annoying with a nice amount of lifesteal(Try to fully stack your thirster with farming a lot )Usually after all that i go Guardian Angel that makes me really tanky and a high damage champ .If the game is still on u can buy something that helps you against their team.A Force of Nature<Randuins<Banshees would be really nice choises.But that depends to you.Well u can see my usual build so try it if u want

Skarner is a very good 1vs1 champ.U encage with q+w+e+q etc.Use your Ulti wisely

It was my first guide so plz guys be gentle :D