For identification purposes, I like "Wildflowers of Texas" by Geyata Ajilvsgi. I'm an organic gardener, so I tend to buy books by Howard Garret for gardening information, but there's not much needed for growing wildflowers. The thing about the book I mentioned first is that is gives information on the type of soils and the regions of Texas that each flower grows in naturally.
I have sown many wildflower seeds over the past few years. For bees, the best one by far is chickory. When it is in bloom, they are all over it. It's not particularly pretty (the foliage) but bees love it. I grow lots of Indian blankets and they don't attract nearly as many bees as I expected they would. Bluebonnets are a good early spring source of pollen and they like Texas thistle (the light purple one) and white prickly poppy is a great pollen source in early summer. The also work both wild milkweeds here (antelope-horns and green milkweed) and they are great for monarch b-flies also. There's also a wild parsley plant that has yellow flowers and I always see bees in it. None of these particular flowers are very "pretty" but the bees think so
So many weeds.......so little time.