Secrets of the Mud Wizards

This book is becoming increasingly hard to find, so please pick up a copy as soon as possible. It is definitely worth getting at any price and is the only book of its kind. I spent a long time finding a good copy of this and finally got it, but it was worth the wait. There is so much good stuff here (I won't summarize as that's already been done above) and there really is something for everyone interested in MUDs. Again, get your copy while you can because this is getting hard to find.

This book takes you from start to finish. Learn the basics of moving and communicating in the MU* world. Then move at a good pace all the way up to coding and building. This is the only comprehensive book I have seen on this subject.