The Art of Polymer Clay Millefiori Techniques: Projects and Inspiration for Creative Canework by Donna Kato
would be the first book I recommend for canes. (you can find it on Amazon.com both new and used and probably EBay as well.)

But, honestly, you really wouldn't have to buy a book unless you felt it necessary. There is a ton (and I do mean a ton) of information on how to make polymer clay canes on the internet. You Tube, expert village, wonderhowto and a host of other sites have specific instruction on making very simple (newcomer) canes to those that are extremely intricate and will blow you away. I would suggest that you go to Google and just do a search for 'polymer clay cane making' and just go down the list. Make sure you open a folder in your "Bookmarks" for all of the bookmarks you're going to want to save.

Enjoy!