Palmistry is totally unrelated to astrology. It is strictly based on lines and other features of the hand. The air, earth, fire, and water designations refer to length of the fingers relative to the length of the palm. For instance, I have short fingers and a long palm, which makes me fire. Short fingers, short palm is earth, long finger long palm is air, long fingers short palm is water. There are a lot of books on this subject, and you should be able to find one for beginners that isn't too complicated.
I used to work with a woman who went thru phases, and she would buy a book, couldn't understand it, bring it to me. As a result, I learned the basics of many of the "forecasting arts" - plamistry, chinese chance, tarot, etc. Astrology was a litttle too complicated, even for me.