Hey guys, I'm GESball. I play a lot of top and adc in games. This is my idea of the way you should build Jayce and where he should be played.
The reason I go for flat AD runes is because the early extra damage makes it easier to farm and gives a little extra damage. You can still go armor pen if thats what you want cause I havnt noticed that much of a difference.
These masteries are just your standard top masteries. Feel free to play around with them and maybe try build him early game tankier.
Building Jayce you must have boots 3 pots. Cloth is possible but i think is less viable. The double dorans is there because Jayce is all about his early game. He needs to get a lot of farm and dominate his lane. If he doesnt then he cant do anything late game. The second tier boots are always just situational, so pick the best for the game. I personally like phage on all my top champs but it is possible to get a trinity force instead. the brutalizer is just there for the early game again. sometimes i dont get it though, you can just go for the hexdrinker instead. The bloodthirster is there to keep up your damage late game. a very good Item for top lane. Since Jayce falls off a little bit in damage late game i always start going a little tanky. Randuins and banshees vail are very very good on him. Both of these are very good.
The skill sequence is always your choice. some people max e first others q. I like q first but e does a lot of damage in melee.
Like a normal top you need flash ignite for the killing power. You need kill power on jayce early game.
When playing jayce top lane you must know all of your limits. Always stay on the agressive. Racking up kills is a must on Jayce. Ward a lot because if you getting that many kills you will be pushed and the jungle will gank you a lot. Remember Jayce has barely any escape ability. Your e q combo is the most important thing. It zones them and does massive poke damage. throw down that combo then switch to your melee form to regen extra mana from your w. Jayce is a very strong lane stomping champ.