The Guild of One-Name Studies is a great resource for locating information on a surname that has been registered with their organization. Their history dates back to 1979 and has proven to be a wonderful resource.
Some individuals do such studies and have not registered with this group. This Wiki page is a place to put links to the various individuals who have created their own website on a specific surname or surnames.
Links to Surname Sites
Bowes One-Name Study (Bowe, Bows, Bow, Boe, Boaz)
Halsted One-Name Study (Halsted, Halstead, Holsted, Holstead, Alstead)