I've been reading a lot on UX lately with the intention of improving the user experience on the custom applications we develop. Most of the resources I used are targeting informational websites. I would like suggestions on resources that I can use that target enterprise & portal applications.
I'd say one of the better ones for application design is About Face 3. A lot of it spends time on interaction design for desktop apps, as opposed to the web (at least in version 2). You can't go wrong with Alan Cooper's work.
Not a book, but the yearly reports of Nielsen Norman Group for intranets would help a lot.