Hello, this is my first build so please give me feedback and comment on my build.
Nocturne excels in melee dps and a excellent ganker. His skill giving him a fear+ red makes him a deadly and imo one of the best ganker in the game(aside from nunu)

The Runes I would get for Jungle Nocturne would be:
3 Armor Pen Quints
9 Armor Pen Marks
9 Seals of Fortitude
9 Cooldown Reduction Glyths

*Armor Pen always makes a dps even more deadly
*The Seals of Fortitude is mostly for jungling, 9 of them gives about 48 health
*Cooldown reduction can be both useful for jungling and also late game

For Masteries:

Since my build does not have armor nor magic resist runes, masteries is very important.
To make sure I have some armor, I must put at least 19 points just to make up for the armor runes. 1 in Offensive for the smite mastery and 10 in utility for Utility Mastery(extend neutral buff)

*Many Nocturne players get 21-0-9 for their masteries. This is because they have either armor runes or flat hp runes. This could work too but if you don't have those runes, my masteries would be recommended

Cloth/5 Health pots
Get Boot and Madred Razor
Use the Madred for Wriggles Latern
Get Youmuu's GhostBlade(Brutalizer First)
Now, you should get defensive items such as Bansees Veil
Build more offensive by getting bloodthirster and a black cleaver

*My Skill Sequence may be wrong above*

-Get Shroud of Darkness First(extra attack speed)
-After Blue, Get Duskbringer(For level 2,3)
-Level 4, Put a point in unspeakable horror(for gank)
-Max Duskbringer Asap
-Put Paranoia whenever possible
-Max Unspeakable Horror next
-Max Shroud of Darkness Last

For Summoner Spells, I prefer ghost and smite.

Smite: Smite is a must due to jungling
Ghost: Always handy for ganking and escaping.

Alternatives:

Flash and Smite
Exhaust and Smite

Start at blue( must ask team for leash)

*Leash-Asking teammates to attack and lure the monster while the jungler attacks the monster

With Blue, Go to Wolves

Then Wraiths

Then Red

Then Golem

By then you should be level 4 with a skill in Unspeakable Horror

Go and gank any lane and hope for a kill

Once again, Please comment on this build and give some feedbacks please. Im planning to make more builds in the future. If you have any questions, feel free to post it and Ill make sure to answer it. Thank you

*If this build was successful please post a screen shot of your score and spread the word!:D