Can you tell me the best place to try and sell these books, and give me an idea of how much to ask?

Hoover - Thompson. A Genealogical Study by Marjorie Harland Barker Diedrich Florida 1985 179/200 and Barker - Harland A Genealogical Study...same author 72/100.

They are huge beautifully bound comprehensive histories of the families, full of photos, family trees, maps etc.. and I would love to get them back to the families concerned. Only bought them from a charity shop because I couldn't bear the idea of them being pulped!

Is there some place that specialises in Geneology books?