Books to read if you're planning a vacation in "Delaware", sorted by average review score:

Daytrips, Getaway Weekends and Vacations in the Mid-Atlantic States: New York, New Jersey, Pennsylvania, Delaware, Maryland, Washington, D.C., and Virginia (4th Ed)
Published in Paperback by Globe Pequot Pr (March, 1996)
Average review score: 

Warning - Extremely Bad Directions
Metalwork in Early America: Copper and Its Alloys from the Winterthur Collection
Published in Hardcover by Winterthur Museum (November, 1996)
Average review score: 

This is about Brass. Not CopperAlthough the books is correct in it's title, "Copper and it's alloys" leading you to believe it's mostly about pure copper items,,,,it's all about brass. The title should have been "Metalwork in America - Brass" Photos are black & white sepia toned. The book is physically well made and on good paper.

Cummings' Vocabulary of Delaware (American Language Reprints, Vol. 15)
Published in Hardcover by Evolution Pub & Manufacturing (June, 1999)
Average review score:
No reviews found.

Delaware Limited Liability Company: Forms and Practice Manual
Published in Hardcover by Data Trace Publishing Company (1998)
Average review score:
No reviews found.

The Delaware Wing-T: The Passing Game (The Art & Science of Coaching Series)
Published in Paperback by Coaches Choice (May, 2000)
Average review score:
No reviews found.

Denny's Vocabulary of Delaware (American Language Reprints, Vol. 12)
Published in Hardcover by Evolution Pub & Manufacturing (May, 1999)
Average review score:
No reviews found.

Denny's Vocabulary of Shawnee (American Language Reprints)
Published in Hardcover by Evolution Pub & Manufacturing (01 April, 1999)
Average review score:
No reviews found.

A Legacy from Delaware Women
Published in Hardcover by Middle Atlantic Press (October, 1987)
Average review score:
No reviews found.

Shipwrecks of Delaware and Maryland (Gary Gentile's Popular Dive Guide Series)
Published in Paperback by Gary Gentile Productions (July, 1990)
Average review score:
No reviews found.

Josiah White: Quaker Entrepreneur
Published in Hardcover by Canal History & Technology Press (November, 1992)
Most obvious was in regards to a covered bridge in Pennsylvania I used to live next to. Armed only with this book, no one will ever find it. That's because it's about two miles west of it's listed location on a completely different road. Not to mention there are no signs to aide lost tourists.
Then there's the mention that the Appalachian trail runs through the Catskills in New York "from Pennsylvania to Vermont". While anyone with an atlas can see it goes nowhere near the Catskills on its way from New Jersey to Connecticut. Did these people even visit these sites in person?
I wish I had read more of this book before I bought it and wasted my money.