Is there anywhere to actually do free research (for geneaology) on marriage & death records in the USA? Every time I find a site, they want money. Does anyone know where to get this information for free?

You could try the LDS Family Search website. I've not used it for a few years but I don't think they charge: http://www.familysearch.org

If you just need the date of death, you can obtain it for free here:
http://ssdi.rootsweb.ancestry.com/