AoE Cheat Sheet: http://steamcommunity.com/sharedfiles/filedetails/?id=548698803
Maximum Info Tooltip Mod: http://steamcommunity.com/sharedfiles/filedetails/?id=643159206

I played Age of Empires 2 as a kid and rediscovered it in 2015. Since then I've been interested in its mechanics and workings. The link above is to a guide with full information on unit stats, attack bonuses, civ bonuses & almost everything else you might want to know.
I'm not a very good player myself as I spend a lot of my AoE time testing & working on my guides instead of actually playing, but I've amassed a fair amount of theoretical knowledge ;)