He's Just Not That Into You: The No-Excuses Truth to Understanding Guys

It's Called a Breakup Because It's Broken : The Smart Girl's Break-Up Buddy

These books are awesome!  I have been in an on-off relationship for almost 2 years--the books on audio are hilarious.  The author is very candid and sarcastic.  I can identify the signs from the very beginning: that he really wasn't that into me, and in some instances I wasn't either.  Also, the authors suggests a 60-day He-Tox, which could also be suggested as a She-Tox, for you guys stuck in the same rut!