Ancestry.com - Ancestry.com is probably the most useful history record search site available. There is a membership fee associated with it, but it does have a wealth of information.
NEMO Genealogical Society - Covers Schuyer, Scotland, Clark, Adair, Knox, Lewis, Macon, Shelby, Marion, Randoph, Monroe, Ralls, Audrain, and Pike Counties in Missouri.
SurnameWeb.org - Surname Web is a fairly useful site. However most links lead to Ancestry.com
Schuyler County Cemetery Listings - This page is on the mother-to-mother website, which I believe is ran by Jim and Paula Yount. Paula has been so helpful to me, and she is such a nice person to work with.
Haverhill History and Genealogy - This page offers an overview on the early history and settlers the Haverhill, MA area - Including the Ayers.
Random Acts of Genealogy Kindness - This site hosts volunteers from across the world who lookup up requested tombstone photos, cemetery videos, locas vital records lookups, and many other tasks.