There's on called "Professional Java 2 Enterprise Edition with BEA WebLogic Server" that I saw on amazon.com. It's published by Wrox but I don't know if it's any good: I haven't read it and I don't know anyone else who has. There are some scary suits on the cover... If you need documentation, BEA have all their WLS documentation free on the web. And I think they distribute it in digital form too when you buy licences.
Hey, sticks and stones baby. And maybe a wee mention of my stuff:
Devious Experiments for a Truly Passive Greenhouse!