Gankplank is an excellent farmer, up there with the likes of Malzahar and Mord. The best part about his farming is the extra bonus gold he gets for using parley to last hit minions. This should seriously be taken advantage of early on in the piece because unless your partner in lane is beefy enough and willing to take the brunt of the damage you may struggle going into things early game.

Gankplanks raise morale doesnt only give a ******ed movement speed boost for you and your nearby allies, but it gives attack damage to your team. Its a great ability to use while pushing a turret, escaping, or even engaging. It can really help your initiator get into the right spot quicker.

Pros
-An excellent farmer
-With a little luck from your crit chance runes (if you followed my rune build), a deadly early game harasser.
-An ability that removes all disables, and a movement speed boost as well as an ult that slows... a good gangplank can avoid a gank easily.
-A very good ks'er :P

Cons
-If underleveled, can really struggle.
-A constant alarm to kill you as soon as you've used remove scurvy.
-Fairly item reliant.
-Not the greatest ult.
-Hella squashy

I roll with the crit chance rune page because i feel it gives him excellent lane control. he may be a bit squashy, but a lot of 1v1 situation will have you critting somebody at least once. good alternatives are full armor pen page. Ive seen somebody run armor per lvl and mr per lvl and that worked out pretty well too, if your a defensive type of guy relying solely and defensive runes that fine, but your early game will blow of course.

i chose ghost and flash because say theres a gank attempt out the jungle, you have scurvy, your e and your ult to get away. of course you can use this in an offensive manner, but its better to play it safe with plank, especially early game, seeing hes such an easy gank target. ghost is always a good summoner spell to have, especially in early game.
alternatives i recommend are teleport, cleanse, and flash if u see a jarvan and ur playin ranked hehe. cleanse doubles up nicely with your remove scurvy. of course if your getting raped by casters and u decide to rock a banshees, you now have 3 spell debuffs, keeping you alive in fights a lot longer.

So you want to play a conservative game. Make sure to parlay minions for last hits and get your heavy bonus gold. Also, if youve follow this guide through well, and you dont get a crit for a few hits early game, chances are you might just have a crit locked iwth you parlay. Just give somebody a quick parlay poke, you crit them or not, doesnt hurt to find out. You are a late game champion for the most, but as long as you get a fair amount of cs, you will get the items you so heavily rely on. Gangplank is a melee dps champ. He's not somebody you just stand in the back and ks people with parlay. He has very good auto attack capabilities with his poison and your crits. Be sure not to be the first to dive in of course, thats your tanks job.

If you've played with plank a lot you will feel even late game he is hella squashy. But with this build you will survive a lot longer and get of TONNES of damage in the meantime. Its hard to look at a late game gangplank with 3500 health, considering youll end up doing 1200 crits after your items elixirs etc. But you will probably be a secondary target even though you pop off so much damage with this build. As long as you time remove scurvy right (say they have 2 stuns and 1 just got used on someone else, so there's only 1 stun left, TRY REMOVE SCURVY OUT THE LAST STUN) its incredibly important early game and late game, as you can even scurvy out of killer ults like warwick or malzahar.