I recommend going to the Arkham threads for any of the 3 games. All 3 have gone through extensive routing, and there's a lot of posts that will help you out. Read through some of the posts to see what your getting yourself into, then try and contact one of the runners (through the thread, or through other means.) They'll do a better job at helping you then I could. I would link the threads, but again, I'm on my phone
Can't help but giggle and remember Robo's donation: Stop mentioning Origins! It's not canonical! (and stuff more that I can't fully remember.)
I never even played Origins. I loved Arkham City and Asylum more than I care to admit, however; once I heard Mark Hamill was no longer doing any Joker roles after Arkham City it totally killed it for me. I'm sure the game is mechanically perfect, but hearing Kevin Conroy playing Batman and not hearing Mark Hamill as the Joker. It just hurts. Admittedly, the guy who played Joker in Origins was REALLY good, but the laugh isn't quite the same.