This is my Jungle Gangplank guide, which focuses on a quick jungle path, as well as a high ganking potential. If you like a fast-moving, heavy, fast-attacking carry, then this is definitely your guide.

I based this off of Saintvicious' Guide, but I changed some of the runes around.

For Runes, I take Greater Mark of Attack Speed for quicker jungling, Greater Seal of Armor for early jungle survivability, and Greater Glyph of Scaling Magic Resist for late-game Magic Resist (you don't get involved early enough for flat MR glyphs to make a difference). I also take Greater Quintessence of Movement Speed for speed into ganks.

Alternately, You could use Greater Quintessence of desolation; both are certainly viable, it just depends on your playstyle: Movement Speed for quickly getting around the map, or ArP for quicker kills.

For Masteries, I take a pretty standard 21/0/9 build. It Focuses on Awareness and Utility Mastery in the Utility tree for jungling. I have tried a 9/0/21 build as well. This build also works, but you give up damage for some survivability and movement speed. If you do go with the 9/0/21 build, then remember to grab the improved Flash as well. It all really depends on your playstyle.

Getting Raise Morale first really helps for beginning jungling. I max this first, then Parrrley, maxing Remove Scurvy last. After the latest nerf on Gangplank, Parrrley isn't nearly as viable a starting skill because of the reduced gold per kill you get.

If you don't get Smite,on jungle gangplank, then you are already screwed. It is ESSENTIAL to have on all junglers. PERIOD.

Other viable summoner spells to use are either Ghost or Flash for a quick getaway or setting up for gank, but I much prefer Flash for positioning; if you are caught out of position with gangplank, you are most likely going to die in a teamfight. In all honesty, if you don't take Ghost or Flash as your other summoner skill, you are putting yourself at a major disadvantage, because you WILL get ganked, and you will die without it more then you will escape.

Gangplanks core is Wriggle's Lantern, Berserker's Greaves, Trinity Force, and Last Whisper. You might argue with the Last Whisper purchase here, but without any base Armor Pen, it makes complete sense.

After these three items your build will depend on what your team needs. I can't stress this enough...BUILD BASED ON HOW THE MATCH IS GOING! If your team needs more DPS, build Infinity Edge and Banshees Veil. If your team needs more tankiness, grab Warmog's Armor and Atma's Impaler.

A couple of other items that I like to buy on Gangplank are Frozen Mallet; this item will let you chase down absolutely any enemy you want, and will give you a ton of health. In place of Last Whisper on occasion I will buy Black Cleaver, especially if they are not stacking armor...but if you are halfway decent with this build, then i almost guarantee you that they WILL stack armor (or maybe a Thornmail against you!).

If the game goes super super late game you can sell your boots and buy a Phantom Dancer in its place; it gives the same movement amount plus more attack speed and a bonus critical chance.

For jungling path, I recommend checking out Saintvicious' jungle path; Credit goes to stonewall008:
Stonewall008's Jungle Gangplank Path
This path starts at wolves to wraiths to golems, then Blue Buff and Red Buff. At this point, you can either gank a lane in need, cover, or just continue jungling until level 6. I prefer to put a little pressure on a lane just to remind the other team you are there, but obviously there is a time and a place for everything.
This path gets you to level 6 the fastest, and also allows you to have both blue and red buffs when you go in for a gank at level 6. Alternately you can go Cloth Armor + 5x Health Potion, but I find without the 2 points into Utility Mastery , you dont have the mana to sustain a gank very well.

Ganking with Gangplank is fairly straightforward. Either drop Cannon Barrage right in front of the unsuspecting enemy, or just use Parrrley to slow them (with red buff), and proceed to beat them down.

After your initial ganking, continue to pester lanes or covering for recalled teammates; you would be surprised how many times I see teammates just give up on a lane after the jungler starts to gank lanes.

In Team Fights, try to just pick away with Parrrley and use Raise Morale on your teammates to sustain, or help them escape. You really need to just stay on the outside until near the end, where you can then go to town on those enemies who are trying to escape; Gangplank just doesn't have the survivability to be in the fray even kind of.

Try to stay with a teammate after a turret has gone down unless you are doing a split-push (4 members distracting in an area, while 1 pushes a lane); while this can be very effective, it is also very dangerous. Moving with a teammate ensures survival, as well as being able to more easily picking off soloing enemies.

A very important thing to remember is that Remove Scurvy both heals AND removes Crowd Control effects on him. Try to save this until you are under CC effects; the heal just isn't that effective on its own.

Gangplank is a blast to play, and hes a damn Pirate! What more could you ask for?