For a plethora of useful struts info, check out
http://www.husted.com/struts/.
I am currently working on a struts project, the first one we've attempted. There was a little bit of a learning curve, but now it seems fairly simple to me. Joining the struts mailing list certainly helped.
If you've ever implemented a web-based MVC application using the command
pattern from scratch, you'll certainly appreciate the flexibility of struts. If you've ever considered implementing such a framework from scratch, there is really no reason to re-invent the wheel IMHO.