Early last year (2005) I installed MySQL on OS X. I was recently faced with the task again and realized I’d completely forgotten everything I did. I just wanted to point out a couple of handy links for accomplishing this task:
http://developer.apple.com/internet/opensource/osdb.html
http://www.osxfaq.com/tips/unix-tricks/week108/monday.ws
The first link discusses installing from source while the second directs you to the binary install. I do remember doing a binary install and that definitely seems the route to take….unless you need to compile with any special options.