Tamil Nadu Natur Reserves in July/August

Hi all, been following this site for a while, but now I am heading back to India for the second time in July/August and I need some advice so have ventured forward to post a thread. I realise it's the monsoon season but as I am a teacher I have no option except to utilise the summer holidays - oh how I miss those gap years!

My wife and I are considering spending a few nights in a nature reserve in Tamil Nadu. We've looked into the ones available, but wondered if anyone could give us information on what type of weather to expect, if it is a god idea or not, and which places to stay they would recommend. Any advice wold be greatly appreciated.

P.S. We decided to go after reading the "You know you're missing India when ..." thread and realised so much of the posts were true. Cannot wait to return!

Can you tell I'm new to this? Also, if anyone has any personal recommendations on other things to see/do in Tamil Nadu/Southern Karnatak/Kerala area from July 24 to August 20th please let us know.
Thanks