Originally Posted by cj2112

I'd really only trim the front edge of the shelves out in hardwood, and that's only if I expected to be adding and removing heavy items frequently to and from these shelves, it just adds a measure of protection to the edges. i'd use a closed grain, inexpensive hardwood such as poplar, although maple, birch or chrry would work. keep in mind your just going to be painting it so it really doesn't matter what wood you use as long as it isn't something open grained.

/edit If your planning on storing those books in these cabinets, DEFINITELY go with 1" thick material for the shelves, you'll be glad you did.