Peter Flach

Based on an AI course taught by the author, this book is an introduction to Prolog programming for artifical intelligence that covers both basic and advanced AI material. The unique advantage of the book is the combination of AI, Prolog, and Logic. It seeks to simplify the basic concepts of logic programming, a useful framework for explaining AI techniques.

Intelligent Reasoning by Example

Simply Logical

Gavin

Quite deep - the other, overgrown and overshadowed half of AI. Part II is a very nice introduction to classical search, though in Prolog, which will be enough to scare away most readers. 

Computational logic is the result of say half a dozen geniuses seizing a field from the philosophers and shaking remarkable things out of it.* It is also not very relevant for 90% of AI researchers today, though the extremely prolific and lively Programming Language Theory and theorem-provers people have inherited some of it and shake out remarkable things. As such, maybe most of this is unlikely to help you.

The site they built around this book makes Prolog as easy as as it's going to get.

Free and fully executable here.

* Putnam and Robinson were philosophers, and the point stands.

Simply Logical Intelligent Reasoning by Example