) offers some free titles (Skyscape: Product Advisor
, unfortunately, none of them are currently available for the BB, but it won't hurt to keep an eye on them.
I find their software reasonably priced, and I like the fact that they use a "reader" which organizes all of your titles in one application.
You can always access some free resources with your BB browser:
The Merck Manual: The Merck Manual
Medical Dictionary: Medical.WebEnds.com
There are hundreds of free drug reference websites, so just do a search and find one you like.