Yes. Absolutely. Blurb takes this very seriously and we respect your content rights. (And by content we mean your original text, files, images, photos, video, sounds, works of authorship, and other material that you include in your books. That’s right: Sounds. We have to cover everything.) For the full legalese, please refer to Section 8 of our Terms and Conditions.
You can do whatever you want with all your original material in your book–you can blog it, publish it elsewhere, make bobble-head dolls, spin off a sitcom, you name it.