The book I recommended is only for Windows users.
Luckily I am a mac guy though :)
There is no difference coding PHP on a Mac versus Windows. Besides the obvious, like the software you will choose to code in, all will look, act and work the same.
If you are planning to code, you can either use Simpletext (os 9, etc.) or Textedit (osx). I would though recommend downloading BBEdit Lite, which is the free little brother of a PHP-native text editor entitled BBEdit. You can download it here:
http://www.bbedit.com/products/bbedit_lite.html
Also, if you are running OSX, your machine comes pre-installed with an Apache Web server. All you have to do (ok, well its not that easy, but I'll cut right to the chase) is install the PHP module to set up your own development environment right on your own computer. That way you can create and edit php files dirctly on your own system without having to upload them to a remote server.
BUT, if you have a PHP server all set up for yourselfand you're paying for hosting, etc. use their server instead. That way you can just learn how to code, and not worry about figuring out how Apache works.
You can use Microsoft Access with PHP, ASP and a whole host of languages. But you can't put an Access database on a mac, because the software isn't compatible with Apple's. The closest database software you will for macs is Filemaker Pro, but that is a whole 'nother issue unto itself.
You can run MySQL (way bigger, more powerful, scalable, and much more stable than Access) and a few other on your mac though.