Mikoto X Touma from To aru kagaku no Railgun Manga

Ok..this is the first pic i color on photoshop so take it easy on me ok it's my FAV couples of all Mikoto Misaka ans Touma Kamijou from To aru majutsu no Index and To aru kagaku no Railgun..i don't own the pic it's from Railgun Manga ^_^ i don't know any coloring methods so pls if anyone know a good place i can start learning with pls give me the link..>.<