http://apologia.securesites.net/store/
The Texas School for the Blind and Visually Impaired offers a number of science resources at their website: http://www.tsbvi.edu/Education/index.htm#Subject
For elementary age students there are a number of textbooks on the homeschool market. But alternatively we might read good science books from the library (and have our child listen to tapes from the Library of Congress, National Library Service).
Nature walks and home science experiments are particularly good for capturing the interest of children, who usually learn better about the real world around them than just from reading a book. They can feel the textures of different leaves, feel the different textures under their feet, hear the sounds of nature.
Thanks to the TSBVI site, I discovered a website which gives a number of ideas for learning to appreciate science with other senses than visual. This includes a neat page where you can play the sound of different types of birds, each one identified and described. I highly recommend exploring this website: http://www.nhest.org/nonvis.html
You can download a free Teacher's Manual for Adapting Science Experiments for Blind and Visually Impaired Students, by going here: http://www.tsbvi.edu/Education/Manual2.doc