I kind of learned the basics of PS through just messing around, so I don't know of any good tuturials for learning the easy stuff.
But what I've used to learn some intermediete-level tricks is <a href="http://www.phong.com/tutorials/">this</a> and <a href="http://www.designsbymark.com/pstips/index.html">this</a>. Hopefully those are helpful to you.