Palmistry.com - Very complete online resource with introduction to palmistry, how it relates to relationships, the different lines, and some Frequently Asked Questions.

Palmistry - Great introduction to history and basics of palmistry.

Ofesite - Another great site for learning about palmistry, don't miss the hands and fingers section.

Palmistry Page - Has interesting description of most of the lines, even the little ones most people ignore.

Handanalysis - Over 20 useful articles with pictures on more advanced palmistry issues.

Handresearch - Very interesting hand research resource with a different spin than above, looks at more evolutionary / technical / philosophical aspects.