travertine cleansers

First off I would recommend having your floor professionally cleaned with a professional scrubbing machine and a heavy-duty stone tile and grout cleaner. 

Once the cleaning is done you will be able to determine a couple of things:

1. If your floor needs actual resurfacing in case that you notice unsightly wear and tear patterns and etchings. If that's the case, then you will need the services of a professional stone restoration contractor that will refinish your floor using a good-quality honing powder. I recommend going to www.stoneandtilepros.com to locate a stone restoration contractor in your area. 
2. If you have imbedded stains that were not removed with the cleaning. I doubt that you will have any of those, but you never know. If you do, then you will have to remove them by poulticing them out, and then apply a good impregnator (a.k.a. sealer) like MB-4 to your floor. Even if you will determine that your floor should be refinished by a bona-fide stone restoration contractor, you need to remove the (improbable) stains first, and, in such case, the sealing will have to be done a few days after the restoration process is finished.

Ciao and good luck,