Accu's advice is pretty much the same as mine, only I think basic MySQL is the easiest thing I've ever learned. By all means use a graphic interface like MyPHPAdmin. I had a fully functional database working 4 hours after I picked up the book for the first time. (Managing a big SQL operation, on the other hand, is an expert-level task.)

PHP -- not so easy. The first book I got was "PHP and MySQL for Dynamic Websites" by Larry Ullman and I recommend it highly. If you start on page 1 and read every word and do all the exercises, you'll end up with a solid foundation AND a working membership program.