So here is the build and etc. I am using. I am only Lv.25 so some of what I have is due only to the inability to add more at this time. I want to note that this is for top lane play, with the occasional Red Buff grab.

Items:
Beserkers Greives => Blood Thirster => Phantom Dancer => Blood Thirster => Frozen Mallet => Black Cleaver

Runes:
Armor Pen Marks
AS Glyphs
Flat Armor Seals
Armor Pen Quint.s

Masteries
24-0-6 (AD focused and 2 in the second row movement speed in the utility)


Let me know what you think, and where I can improve this. I've had moderate success with this build minus the runes, and mysteries that I can't reach yet in normals, but I really want to cement my play.

Well. Your trying to build like an adc.
Your not an adc. Your more of a tanky damage type. I like how you have a frozen for slow and health, but that doesnt make you tanky.
I would suggest bt(replaces you wriggles), randumins, FoN, frozen mallet, tabi or mercs,and possibly wits end.
other routes could be GA or Maw of Mal
Masteries: 9/21/0 Increases tankiness while getting the armor pen

im a lvl 21 and i prefer jungling with nocturne what masteries, should i use?

your major problem is your building a glass cannon on a champion with no defense of his own other than a spell shield that only blocks 1 ability.

your already getting high AS from 1 of your abilities, and quite a bit of AD from another, so you really dont need to be stacking so much.

your also a melee champion who will be an easy target, theres no escape for nocturne so you'll want to build defensive cuz you will be targetted since you are a glass cannon. not targetting you will be a very foolish idea for the enemy team

so what you will want is things that will be offensive and defensive at the same time. build a bit of health with frozen mallet, or omen, that'll give a good mixture of survival and utility, for MR you might wanna look into things like maw of mortimalus and wit's end.

so focus more on what you lack instead of stats you already excel at.