Thanks for the constructive feedback :)

You need to have more explanation as to why the support fits jayce well. Why do I want Thresh or Taric? Soraka sounds pretty solid for infinite spam too. You have to provide support for your statements.

I would like more information on the items section too. Writing a paragraph about each item should be very easy to do. Why is it good on Jayce, why Botkr? Why not PD or statik shiv? There are many varieties and you have explain why you chose a certain item.

I would like better formatting on matchups section too. I'd also like you tto further explain your masteries. Why should you put points into crit damage rather than magic pen for e? (Should be obvious for ad carry, but you should still explain these things.) Be thorough in everything you write about.

The item build section at the very top should be short and concise. None of this 40 icon stuff when you could easily show a build with 6. Also, don't include a matchup section if you aren't going to say anything relevant on any given matchup. People can look up skillsets on lolwiki if that's all they want to know. Either include some quality matchup specific information or get rid of the matchup section altogether.

Holy shit this guide is awesome, thank you! <3

Done ^_^

Runes, masteries, summoner spells, and late game all need work

You need to heavily expand on your skills, item build and phases of the game sections. The intro should explain exactly what makes Jayce a better ADC than a top laner and question any concerns people may have. Also crop your screenshots of the your runes and masteries pages to only show the relevant section like so: http://cache.gyazo.com/1ae28566eef70af4bd0f8a9f682f8e27.png

Overall your guide could be more in depth, explain more details, combos, tips about skills and exactly what a new player of Jayce bot lane should be doing. Don't assume the reader knows, explain explain explain your choices.