Reddit mentions of Becoming Orgasmic: A Sexual and Personal Growth Program for Women Revised and Expanded

Have half a dozen:

• Come as You Are: The Surprising New Science That Will Transform Your Sex Life by Emily Nagoski. A very accessible summary of recent research; especially good about understanding libido issues.
  
  
• She Comes First: The Thinking Man's Guide to Pleasuring a Woman by Ian Kerner. A primer on oral and manual technique, for anyone who loves a woman.
  
  
• Becoming Orgasmic: A Sexual and Personal Growth Program for Women, Revised and Expanded by Julia Heiman & Joseph Lopiccolo. A first-rate guide for women who are struggling with inhibitions and/or looking to make orgasms less elusive.
  
  
• Heterosexuality by Masters, Johnson, & Kolodny. An excellent reference work and troubleshooting guide, at least for straight people.
  
  
• A Beginner's Guide to Good, Great, and Amazing Sex by Shakti Amarantha. This is a "book" I created by collecting 26 of Shakti's best articles.
  
  
• Extraordinary Passion: The Art and Science of Modern Tantric Sex by Shakti Amarantha. And this is Shakti's how-to guide to the earthy, secular kind of tantric sex.
  
  The first two are in print. The next two are out of print, but almost always available in good condition from Amazon. And the last two are free online.
  
  I highly recommend all of these.

If you go to the SO30 Wiki, and look under Orgasm Problems, you'll see a link called "How Can a Woman Become (More) Orgasmic?" It leads to a long reply to a similar question a year ago, describing the many things that can get in the way, and there are a lot of links to other helpful resources at the end of it.

I particularly recommend Betty Dodson's blog and Becoming Orgasmic: A Sexual and Personal Growth Program for Women, by Dr. Julia Heiman and Dr. Joseph Lopiccolo. I'm also a fan of meditation, sensual massage, and anything else that works for stress-reduction.

Good luck!