Family History....book writing and publishing can be an awesome task. My suggestion is to first decide the type of family history you are thinking of publishing, put that together in some format, polish it and when satisfied then start looking for a possible publisher...Others have given you some Links to help in search for a publisher.

Are you looking at a narrative type book or a genealogy oriented book? Will you include photos of family, scanned documents (census, vital records, etc.)? Is it ancestor oriented or descendant oriented, single family or multiple families (maternal and/or paternal)?

The above are just a few of many questions to be considered. Below is a AfriGeneas thread on the subject.

Best Wishes,

Art Thomas