I have gluten intolerance (Celiac Sprue, biopsy diagnosed) and made the same move as you did: went to the book store and library. After checking out a number of books and getting a feel for things I have made a few purchases.
Oddly, as I normally don't go in for the series, one of my favorites is Gluten-Free Cooking for Dummies by Danna Korn (cracks me up! Corn does not contain gluten! /img/vbsmilies/smilies/crazy.gif) and Connie Sarros. Once we found, tested, and enjoyed the Feather-Light Crepes recipe on page 141 we knew this could be done!
Another of my favorite is You Won't Believe It's Gluen-Free by Roben Ryberg.
My approach to gluten-free eating is simply: buy raw and cook yourself.
I avoid processed foods for the most part, even those labeled gluten-free. They are frequently higher in fat and calories than they gluten containing counter parts. If you can get something in it's natural state, wash it and cook it in your, fresh gluten free pans, all the better. I have adjusted many of my old standard recipes to be gluten free and we eat happily at our house which is a completely gluten free zone.
Beware cross contamination. /img/vbsmilies/smilies/cool.gif It lurks everywhere.
Best of luck and she is lucky to have you on her side.