Sources for information on antique furniture

I have some antique furniture that I'm trying to find out more information about. Does anybody have any on-line sources of information? Failing that, does anybody know of any good reference books on the subject?

I've tried searching for the specific company that made one piece, but other than finding out they were in business somewhere in the early 1900's, I didn't find any more information. Thanks for any help you can give me!

The only thing I can think of is the Antiques RoadShow on PBS, and other similar shows.

Sometimes they talk about good antique books for research or the credits list books on antique furniture etc. that were used for the show.

There are many good reference books you can check out at the library (alot cheaper than buying, 'cause they're real thick! If it's particularly rare or valuable piece, you might want to go with a professional appraiser. Just make sure it's not a dealer in disguise who will try to lowball the value and offer to buy it from you! (Then sell at a tidy profit!) This happened to my mom with an incredible spool bed she had...

It's mostly for insurance purposes - we need riders to cover them if they're very valuable. Anybody know a good appraiser in the area?