I've been pondering this for years. I'm very, very good at some things such as installing and hacking scripts. What I lack is the ability to create my own stuff. So, I've learned that the best way to learn php/mysql is to install the package on your machine so you can work with it locally and then play.
I was using FileMaker. FileMaker is a great database when you want the ease of use with pointing and clicking. It has a lot of easy-to-use built in functions and calculations that you can point and click to find.
What I found extremely difficult with FileMaker was creating difficult databases. I know it can be done, but with my knowledge of sql, it seems to be limited in some respect. Yes, it is a relational database engine, and yes, it can do some very great things but if you've learned on a different kind of relational system it just makes things difficult.
It is also very expensive. I can't imagine creating a package for a customer and then telling them that on top of the hourly amount they owe me that they now owe me another $700 for the database application plus a possible seat license. Yikes! Save that for the big guys like Oracle and Sybase (is Sybase still around?)
I'm sure that I can learn to create very nice applications from scratch using mysql and php. I just need to learn the php code a little better. Hacking and manipulating comes easy to me. It's putting it all together is what I need to work on and that's what I'm going to do with all my databases that I've created in FileMaker Pro. I'm tired of paying the obnoxious upgrade fee for FileMaker so here I go to the mysql world completely!