Jungle Gangplank in my opinion, is probably one of the best hands down solo top champs in this game right now. His sustain with his W and the amount of harass he offers with his Q is only matched by people such as Irelia and Morgana. But he has something over both of those champs that is one phrase or nickname that we have all taken into account. "Critplank" and "fed" in a positive manner for that team is the last thing you would want to hear in a game of League of Legends.

For my personal build, I like to focus a lot on two certain types of marks in my runes

Greater Mark of Malice x5
Greater Mark of Strength x4

The Main reason for this selection, say, over 9 of either is so that way at the beginning of the game you aren't just so heart felt on only getting crits, because you can still deal a decent amount of damage without it when you have this extra push from the marks of strength on your side.
For the seals and glyhs most of it actually pretty standard for most melee champs, but with some different types of changes to just help with your sustain. For the seals I have:

Greater Seal of Resilience x5
Greater Seal of Vigor x4

The reason I chose the seal of vigor is because it gives you that extra health re gen to help you compete with champs such as Garen and Morgana who normally would easy be able to out sustain you because they have easier ways of healing than you and eventually overwhelm you and hit your tower.

Lastly it is just the standard glyphs for this champion:

Greater Glyph of Warding x9

The masteries in this build are sort of simple, basically you are doing 9-0-21 masteries picking up armour pen in offence and gold income per second and experience and cool-down parts as well to make sure you can maximize your domination in solo top lane.

To get the fullest out of the word "Critplank", basically you want to get your brawlers' gloves first to make your crit chance at the beginning just about or if not over 15% at level 1, which is kinda huge when you think about it. Then as soon as you can recall back and buy a philosopher's stone for extra regen and gold income and also pick up your boots of speed (the brawlers' gloves should pay themselves off by about 5 minutes if you get all the last hits possible).

Next you want to go right to your PD (phantom dancer). So you want to power through gold to make sure you get it, just don't throw off your jungler by doing so. But try and make sure you get the kills over your jungler, because that'll just help you that much more in powering through to the most useful item in your build.

Then just take your time and harass when you're building to your infinity edge, try to buy either both build items at once, or just try and buy the whole thing at once, mainly because I hate just having one or the other of either item because they leave out each other alone so it can be hard to choose one over the other if you only have enough gold for one.

Nextly, for more survivability, you want to pick up the warmog's armour and the guardian angel, this way you get over 3000 health while dealing crits like a mad man, you can also come back to life and probably get ANOTHER kill in your team fight, or finish off your little 1v1 you were having.

Basically the skill sequence you want to have here is you want to power level through your Q and /or your W or E depending on how strong you are laning against your opponent. Pick up the E if you are doing strong to do even better, of pick up your W second to make sure you can stay alive for longer and catch back up.

The summoner spells are meant for two things, commitment to your team and making sure that the fcker dies. Teleport is to help your team out with different ganks (pop your ult and then go to that location is pretty dirty), and ignite is for those people who like to use stupid healing moves (fiddlesticks, dr,mundo, vladimir) and to make sure that if your opponent is at basically 50 health, that ignite gets you that kill that you may very much need.

Now we can talk about the different pros and cons that critplank has

Pros

If he gets first blood, gg.
Very good sustain if played right.
Great mid gamer champ to play.

Cons

Runs through mana quickly at beginning if played wrong.
Has a hard time escaping before level 6.
Hard to come back late game if you had a fail early game.

Overall, I would always pick Gangplank as my solo top champion if I had the choice, because the amount of promise he has is a very high amount with all of the different things going for him, and makes him a very strong champ to pick up especially when paired up with a jungler that can stun or suppress. Anyway this has been McDirtson on my first build and I hope you have been able to learn about something maybe a little different than most people's builds and my insight on why I did certain things. Thank you.