What you should do is first remove all the trim around the edges. Look for nail-heads. If you see some, there's a good chance the entire floor is nailed. If not, it's probably glued. Now, depending on the AGE of the floor, who knows how it's being secured.
If the floor is nailed, you need a Nail Set/Tap to 'push the nails through the wood in order to loosen the boards. If you just rip them up, you may end up destroying the wood! The same goes for the nails in the grooves. (Just tap them through, and into the floor, whereafter you'll just hammer them INTO the sub-floor.)
If the floor is glued, you'll have a tougher time salvaging the floorboards. In fact, once they are removed, you may need to have them planned so they're all the same thickness.
Consider talking to a local Preservation Society. Stop by your Municipal Office and ask around for a contact person. Stop by one of the local Historical Buildings in town for leads too. The 'experts' they put you in touch with should be able to help you (or guide you.)