Im not a Progamer, just so that u know.But i like playing jungle skarner and i nearly always own totally.If you read this guide and think something is wrong or dont like something say so in the comments.I'm open to criticism but not flaming.

Pros:
-extremely fast jungler
-Aoe constant damage
-sustainable in jungle
-Beast in lategame if you gank successfully
-good counterjungle
-He`s a skorpion

Cons:
-no earlygame stun
-underrated
-I cant think of any more
-Oh yes..... he's purple

Now that were through this im going to tell you the jungle path.In my opinion it is very nice and fast and easy.
Wolves->Blue->Wraiths->(gank)->Golems->Red->Wolves->Recall
I managed this quite easily.If you see an oportunity to gank-- ALWAYS go for it if you have enought health and mana.

With Skarner it is hard to gank midlane early so you should focus your ganks on bot and toplane.
Engage from behind with your W skill and once your close enough spam your Q skill.If you manage to hit the Enemy twice with ur Q skill u've got them pocketed (unless they use flash).If they use Flash be sure to gank again in a minuite or so because then you can kill them easily (unless the allies in that lane suck and have no hp).

In the teamfights be sure to enter the fight right behind your tank with your W skill.Use your Ult on the enemy AD carry or tank depending on if your team wants to get rid of the tank or the enemy damage.I prefer to pull the AD carry.Once you've ulted someone start spamming your Q and using your E skill for healing.Always remember to use your gunblade in these two situations:
A:You're chasing the rest of the enemy team and they're getting away.
B:You're at low health and need to put out a last bit of damage.

I go for atack speed marks because with them i can jungle very fast,u can also go for arpen marks to scale better into lategame.Armor seals allow me to jungle fast with my marks but still be very sustainable.I dont really want to build a magicresist items in my core so i take mres/lvl glyphs.I take arpen quints because i like them and arpen is always good.

I go for a 0/14/16 build so that im fast and sustainable jungler earlygame.Skarner scales well enough into lategame if he has a good earlygame (successfull ganks) and that is possible if u always have enough health for it.Most important masteries: Summoners Resolce,Vereran's Scars,Siege Commander,Awareness.

There is nothing much to say about the wriggles.... It's important as a jungler cos of the chance that u deal a ton of damage to a minion and cos of the free ward.Merc Treads are always good cos of the tenacity (cc reduction).Sheen into Tri-Force is a MUST on skarner because all of the effeccts are AWESOME, specially the effect of sheen.Gunblade makes u even more like a boss with AD,AP lifesteal and spellvamp.At last round it of with a banshees for being more tanky.

Impale is better than Shattered Earth is better than Seismic Bastion is better than Ixtal's Impact

Smite: MUST for a jungler
Flash: Awesome spell.... synergises really well with skarners ult

Alternatives to Flash
Ghost: Good spell too... provides a nice chase/escape mechanism
Exhaust: Good for early game ganks but lack of escape mechanism
Surge: Good for fast jungling,teamfights and ganks.... but no escape mechanism at all

I've made this chapter because i see some junglers just never use theire wriggles lantern and dont buy wards so here is a map with ward locations taken from How to make a guide by Jhoi Jhoi:
Yellow: Vital to protect the jungler on your team
Blue: For protection depending on which lane you're on
Red: To guard Dragon and Baron
Orange: In order to Counter-Jungle

I hope you find this guide helpful.If you have tips/criticism please comment it.
And again-->Im not a Pro, just an ordinary player of the better persuasion ;)
Also, this is my first guide so dont bee too hard on me pls :)