Hello this is my first Mobafire-Guide so don't be too hard to me ;)
Nocturne is my main and that since he came out. He's one of the best 1vs1 fighters in the game and also one of the best/fastest junglers. And at level 6 u don't have to care about your ganks if they have flash.

Also hes is a realy good laning Champ. Most people say ''OMG NOC WHY DONT U GO JUNGLE??? NOOB!!!'' and after the game I only see ''gg nocturne''.
And to all the people who still say ''Nocturne is a jungle Champ''... Riot didn't listed Nocturne as a jungler. And believe me if you see me once laning with Nocturne, you will change your vision about laning Nocturne.
Play Video Just to show you how I play with Nocturne (My friend recorded this Game with ''LoLReplay'' and he died so... it turns black :P)

Jungle: For jungle Nocturne I go for 21-9-0. Why? Because I want to gank fast without going back before. Most people who jungle with Nocturne are going back at level 3. Not Me!!!

Lane: Well yea... there's not realy much to say for it. I just use offensive masteries :D

Jungle: Here I start with a Cloth Armor and 5 Health Potions. But why don't start with a Vampiric Scepter? I'll tell you why, because the first time I go back I want to get a Madred's Razor (and eventually some Boots) I don't want to run around with half items!

Laning: Well lane or jungle I always go a bit deffensive with Nocturne. So I can stay alive in teamfights as long as I can. And also it makes me more difficult in a 1vs1 :)
I start with a but if you want to, you can also go for the .

Pros:
Fast Jungler
Able For Jungle and Lane
Life Steal on level 1 because of Umbra Blades
Nice Ganks at level 6 (and earlier)
passively gains attack speed without items (if you skill w)
One of the best Ultis in the game
Can join teamfights from a far distance easy with Paranoia
Can chase backdorer with Paranoia
Great escape Oppertunities
Has a little Banshee
Has the best skin in game (Frozen Terror Nocturne)

Cons:
Mana hungry early-game
Focused in Teamfights
Can be Squishy in early-game
Paranoia has a pretty low range on first level

Of course i skill Duskbringer first for the jungle so I'll get bonus attack damage and for the lane to harras the enemies. But why do i max. Unspeakable Horror at last? Well it's pretty simple. In the Mid-Game when I'm about level 10 I don't have any attack speed items except of the boots... so I'm going to skill Shroud of Darkness because if I gank I could have skill Unspeakable Horror 3x which allows me to fear the enemy for 1.5 seconds but why fear him a half second longer if you cant attack him more than once in a second so i prefer to skill Shroud of Darkness to have more attack speed. And 1 second or 1.5 if you have 1 more in the lane u fear one of the enemies and the other one is running away, your team won't need longer than a second to take him down! That's why I skill Unspeakable Horror at last.

Nocturnes passive is Umbra Blades, This is what makes Nocturne one of the best junglers in th game. It deals +20% physical damage to nearby enemies every 10 seconds and also it heals Nocturne. And if it's not already good enough, every basic attack reduces the cooldown of the passive by 1 Second!

Duskbringer is Nocturnes Q, with this spell Nocturne throws a shadow hand which leaves a dusk trail behind hit (every enemie wh gets hit will leave a trail behind himfor a short time too) while Nocturne is in the trail he gains bonus movement speed and attack damage.

Shroud of Darkness is also important for Jungle Nocturne. Nocturne passively gains attack speed (which works well with Umbra Blades because of the CD reduction), if Nocturne activates it he will become a shield for a short time blocking the next spell. Shroud of Darkness can save your life so activate it wisely!!!

Unspeakable Horror is not realy important for the jungle but you will need it for the ganks! Nocturne can put it on an enemie and after a short time the enemie will be feared.

Nocturnes Ulti will flash look like a b***h. If you try to ear the enemie and he flashes away dont worry just chase him with Paranoia and everything's fine :)

Jungle: No smite no jungle!

I usually go for Ghost as my second spell but you can also go for Flash or Exhaust. The rest is not really necessary.

Lane: When I play Nocturne in the Lane I run with Exhaust and Ignite

Also good is:
Flash
Ghost
Clairvoyance

Why CV? For your Ulti, if there is fog pop up CV and you got him.

Play Video
I start at Blue (you can ask for a pull but actually you won't need it) use Duskbringer first then start hitting (if someone pulls wait till the golem attacks you so you can be sure that you stay in your trail). You can use Duskbringer as much as you want, but I prefer to use it only once. Smite him when he has about 400-500 hp. Now skill Shroud of Darkness and kill the Wolves with Duskbringer and auto attacks(Focus the brown Wolve). Go to the Wraiths and kill them (Focus the Blue Wraith). Kill the Lizard with Duskbringer and Smite. Then you go to the Double Golems and kill them with Duskbringer and auo attacks too.

You should be level 4 now and you should have about 75%-80% of your HP YOU'RE READY FOR THE GANK!!! Use Ghost so it will be easier for you to chase the enemie. Then put Unspeakable Horror on him and hit him with Duskbringer (Don't worry if he uses Flash it is still a succesful gank even if you don't kill the enemie) now hit him with some auto auto attacks and... ''You have slain an enemy''

Now go back in th jungle and try to get 1050 Gold (If you killed the enemie with the gank you only have to kill the Wolves and you have the money, if u didnt killed him go back with 700 Gold to get the Madred's Razors.
The rest you should know.

3 little things you have to know:
Always ping before a Gank.
Help your Teammates, even if you have to stop your jungle path for this!
And hold their lane if they have to go to the base!

You want to play Nocturne in your next game but somebody else is gonna jungle already? Or you're just tired of Jungling? Well i think that I can help you there :D

Nocturne is a great farmer because of Umbra Blades but you can do alot more with your awesome passive! Imagine you're about lvl 3 you just lost 50% of your life... well it's not a big deal Umbra Blades can help you! Just wait for the next minion wave, there will be 3 melee creeps and 3 range creeps just walk behind the melee creeps and the range creeps will automaticly attack you, now walk back in front of the melee creeps so the range creeps will follow you now they're all close together hit one of the creeps and you will get about 100-150 HP back, do it with the next wave and your life shouldn't be a problem anymore!
But that's just one of many things what akes Nocturne such a great Laner. Now I'll tell you why I'm going into a match with Exhaust and Ignite. If you start a fight Exhaust the Damage Dealer hit him with Duskbringer (try to stay in the trail!!!) fear him and because you both focused him and he was exhausted it's like a 2v1, because of the Exhaust he will make no damage but u will do because of the trail you stay in, then he will get feared yet, only thing you will hear is... ''you have slain an enemy''
Paranoia is not only useful to chase an enemy! No it can easily turn a 1v1 into a 2v1 just activate it the enemy will be afraid of you and try to run (if your teammate isn't too low) now your teammate can deal some damage and there you come jump on the enemy and kill him. This also works with teamfights if your team has a fight activate Paranoia and join it, because they hear ''darkness...'' they will be scared and they want to know where you are, that will make them forget the teamfight more or less if you go in then everybody's is on low HP while Nocturne is full you can score a PENTAKILL!!!
Also Nocturne has great Escape Oppertunities if you're getting chased fear him with Unspeakable Horror throw a Duskbringer in front of you so you can run faster.
That is all you have to know about Nocturne in the lane! Everything else you have to learn by yourself, not everyone will have a 20-2-13 score with their first match as Nocturne. So practice, practice, practice!