To get a well-rounded view, I believe that you should read as many books on Palmistry as possible.  Each book has a truth that will help you on your journey to become an excellent palmist. 

Here is a list of books I recommend.  When you click on a book cover, you will be taken to amazon.com where you can order your book from them.  We are very proud to be associated with amazon.com and to be able to offer these books to you.

Instant Palm Reader : A Roadmap to Life (Llewellyn's New Age Series)
by Linda Palmascope Domin

I have found this book has many of the minor line markings that I love to find in people's hands.  I have this one in my collection.

The New Palmistry : How to Read the Whole Hand and the Knuckles
by Judith Hipskind

Judith's books are very clearly written and some are out of print.  This is a new one that I believe you will enjoy.  Try and find her other books as well.

The Complete Book of Palmistry
by Joyce Wilson

The Practice of Palmistry
by Comte C. De Saint-Germain

This is a very old book that has been reprinted.  It is a must for every palmist.

The Little Giant Encyclopedia of Palmistry
by Nathaniel Altman

Information is presented in an easy to find and easy to understand way.  He also has several that are out of print.  Try and find them as well.

Palmistry : The Language of the Hand
by Cheiro

Probably the most famous of the old palm readers.  This is also a must for your collection of books on palm reading.

Art of Hand Reading
(DK Living)
by Lori Reid

This book also has information on some of the minor marks and mounts that I find invaluable.

May I See Your Hand? Palm Reading for Fun and Profit
by Myrna Lou Goldbaum

You may not want to follow all of her suggestions, but some of them are very good.

Pictorial Key to the Tarot
by Arthur Edward Waite

A Classic - classical interpretation of the cards