I am going to keep this plain and simple. I don't know how to link all the little pictures and I really don't care. If you need picutres to learn how to play a champ then please don't ever play with me. I don't like indepth builds for champs because honestly everyone is going to play them differently. This guide is an in and out kind of play style which I tend to like. It means you have balls and aren't afraid to attack and harass but you also know when to run when it is a lost cause. GP is a harassment character. You have so much burst damage so you are almost like a caster but only the oposite. Please by all means though don't be afraid to melee. Your passive posion hurts a lot and all of your attacks late game are going to crit so if your team goes in then go in and don't run unless they all die before you get there. Also don't save your ulti. Use it every chance you have it up to gank or to save a player from a gank.

Marks- Armor Pen(If you think anything else is better for this spot you are wrong. This will give you 15 arp which is all that you need for this build it is meant for early game harrassment against champs with high armor like rammus. Late game your crit damage will be pretty much insane no matter how much armor they have and that is what other champs are for. This build doesn't give you the ability to 1 vs 1 against anything other than a squishy so don't. Leave that up to melee champs like yi, garren, xin, etc)
Seals- Crit Damage(This is what makes you overpowered as hell you can go with attack speed but it will not help you with this build and honestly while GP does need attack speed it is only useful in a team fight. If you go heads up against a fed xin zhao and try to melee him you are an idiot plain and simple. GP is meant to hit and run, hit and run, hit and run. You have to learn how to kite and use his abilities to your advantage.)
Glyphs- Cooldown's per lvl( This spot can be used for whatever really. A lot of people like magic resist but with this build you will two shot any caster so what's the point. Your "R" ability is on a long cooldown and you cant afford to build for cooldowns. If you get caught alone it is your own fault for not watching the map. Plus your remove scurvy will get you out of any cc you might encounter.)
Quints- Crit Damage(Again this is what makes GP and this build such a pain to play against. Everytime you get hit with his "Q" ability you are going to loose half or more of your health.)

This set up will help you lvl the fastest and do the most damage. If you want more survivability then go down the defensive tree but it doesn't work with this build as well.

Start with aand build this intoYour objective in the laning phase is to pay attention and to use your skills in the right order. First off look at who you are laning against. If they are not agressive then harass heavily which will often result in a first blood. If they are agressive then last hit as much as possible and try to set up a gank. In order to gank with GP you want to get them to about half health first and make sure you have enough mana for Raise Morale and Parrrley. Then you want to pop Ghost and Raise Morale at the same time and Parrrley them asap. As soon as you get to them exhaust them and keep hitting them until Parrrley is up and hit them again with it and they should be dead at this point. This is almost always a garenteed kill if they are alone or if you have help from your team with crowd control and focus firing. Make sure again to use your Ulti as much as you can but also be smart about it. The only time you should use it is if you have set up a gank, saving a team mate from a gank, or protecting a turret. After this if you haven't got yourthen finish that then you want to make anafter this grab aand you are a force to be reckon with. Then you want to complete the. After this the build becomes up to you. I like to get a little more attack and movement speed from aand then look at who I am up against. If the match lasts this long it is either a really good game or neither team is pushing so grab aand set up a gank. This gives you a little trick. What I like to do is to lure with it. I wait until the enemy team cc's me and blows there abilities on me then I pop Remove Scurvey(full heath again thanks to theand Raise Morale and GTFO!) At this point your tank has already jumped in and taken the hits while you and your team comes back in because they are no longer focusing you and kills them all with an ace. This is again how I play GP but I felt it was important to make this build for the simple fact that most people don't play him wrong necessarily it is just not worth playing him if you play another way in my opinion. I have over 200 wins with just using GP alone and with the way they have nerf/buffed him this is the way to go to insure a victory or at least damn good game(team dependent). Please don't rate this until you try it and I am always up for hearing opionions and suggestions.