There are a number of good books for lawyers covering trademark law. One book that I believe is useful for both lawyers and laypersons alike is Trademark Law: A Practitioner's Guide by Sigrun D. Kane. The book is published by the Practising Law Institute, 810 Seventh Avenue, New York, New York 10019 and is currently in its fifth edition. It provides a good overview of the law and is full of practical advice. The book gives the reader insight into the world of trademarks in an accessible, user friendly way. There are illustrations to explain many of the concepts and conflicts discussed in the book.
The book gives insight into the workings of both the Trademark Office and the Trademark Trial and Appeal Board. It is not a substitute for legal advice, but it can give a leg up.