Books everyone should own:
The Source: A Guidebook Of American Genealogy (3rd edition) - this is an indispensable guide to genealogy in the US. Buy it! This book actually spends very little time on my bookshelf.Ancestry's Red Book: American State, County & Town Sources (Third Edition) - Gives information on where genealogical information can be found on state and county levels (archived and internet). Tells county by county when different records were kept. Very useful.
Map Guide to the U.S. Federal Censuses, 1790-1920 - indispensable in doing census research. This book describes the formation of new counties, the changes made in county lines, and discusses various aspects of the census over the time period of 1790-1920.
The BCG Genealogical Standards Manual - Discusses the standards professional (and hobby) genealogists should follow.
Wellman, Iowa Centennial 1879-1979 - A history of the town of Wellman in Washington County, Iowa. I'm happy to do look ups for people. An every name index can be found here.
Cumberland County Pennsylvania Marriages, 1761-1800 - Once again, I'm happy to do look ups.
Pennsylvania German Roots Across the Ocean - A collection of articles from the Pennsylvania Genealogical Magazine. The book has an every name index. I'm happy to do look ups.