I found this blog which is written by a trauma therapist who specializes in treating DID. She has written a series of articles about how to increase internal communication, working with difficult alters, things to work on in therapy etc. Personally I think they are extremely valuable. I also saw that some people had placed comments or asked questions and received replies from her too.

I highly recommend checking this blog out. There seems to be a lot of very helpful information on there.

http://discussingdissociation.wordpress.com/