I am aware some people are having difficulty trying to find all the riddler riddles, riddler trophies, joker teeth and arkham chronicles etc. For those of you that are I have found and used a great guide that was posted up at Games Radar which was extremely helpful in helping to get the achievements and unlock all the challenge rooms.
The link to the guide is HERE
I hope this helps :D
P.s. the only thing this guide does not include is where to find the LAST chronicle for that, please refer to THIS