If you haven't mastered the FS, AP, AP Nuke and AP Tank build, this guide is not for you as you would be playing her in a radical manner. I spent the whole season 2 mastering every possible build that I can think of, testing every theory that I have in mind and proving that AD Sona is possible!
These builds are all used in rank games. I never play normal or custom games and sad to say, my season2 ELO is 1090, thanks to my experimentation. Not that I suck in playing but always keep in mind that it is a 5v5 match. Even if you'd do a 100 kills(which I think is impossible) and your team doesn't have coordination, your team is really destined to loose. Modesty aside, as of December 3, 2012, I already nailed down 78 opponents in 1v1 fights; been defeated 6 times though.
... I'm still working on something that's why I can't finish this guide yet. But if you got questions, you may send me a message here.