I've been writing to publishers to get permission to write and perform plays based on several books I like.  Does anyone have any experience doing this? Any information I could get on this subject would be greatly appreciated.  Thanks

Don't know about America, but over here plays are often published with a licence to play them, there are a couple of publishers that specialize in plays, so I'd just visit their website. If you'd like to film it, you might want to ask their permission first, they might also charge extra for that licence.

It can be a long process but just stay with it. You are going about it in the right way. The first step is to contact the publisher. Often they direct you to the author.  If you can get a hold of contact information for the author themselves it does not hurt to contact them also if you hit a dead end with the publishers themselves.