For deaths outside of New York City, deathindexes.com is the best place to start, as it contains a directory of links to online death indexes, organized by state and county. Included are death records, death certificate indexes, death notices and registers, obituaries, probate indexes, and cemetery and burial records. Note: Some of the links in this directory will take you to websites that require a paid subscription, such as Ancestry.com, or that charge a fee per document viewed, such as ObitsArchive.com.
The Church of Latter-Day Saints’ Family History Library has microfilmed death certificates, death certificate indexes, obituaries, and cemetery records from many towns/cities and counties across the U.S. Most of these microfilms have been digitized and are now viewable (but not necessarily searchable) on the Family History Library's website. To determine whether there are any microfilms relevant to your research, search the catalog for the name of the town/city or county where you believe your ancestor died and select the relevant category (Note: death certificates will be found in the “vital records” category). Click on the camera icon next to your desired microfilm to open it on your computer. If there is key icon next to the camera icon, then that microfilm can only be viewed on a computer at a Family History Center. To find your nearest Family History Center, click here.