Part One: Whatchew Need.

You may think yourself something of a Drupal master because your Fantastico installation was smooth and easy. And, congratulations to you. Even noodling through a Fantastico install of Drupal can be hard for a goddamn idiot.
Now you're ready to install a copy of Drupal on your local box because you want to do some testing or use some of Drupal's advanced CMS features locally. Good for you.
So, here's what you gotta have on your machine before you start. Think of this list as a "System Requirements." like you might see on the back of your copy of The SIMS 2. If you'd have bought the Sims 2, instead of stealing it off the bittorrents, you bastard.
There is a list of Drupal's Requirements on Drupal.org. It's got a lot of info there and you should read it. It will make you smarter and prettier. The rest of us just install XAMPP.
XAMPP will load your machine up with an Apache, distribution containing MySQL, PHP and Perl, which, along with Drupal source, are the ingredients for delicious Drupal-pie. Souflee. Crepes. Some kind of pastry, anyway.
Part of the reason I was inspired to write this is because I had been struggling along, trying all kinds of crazy and strange ways of getting Apache, MySQL and PHP installed on my mac, when, lo, like a light from the heavens, Steven "Sven" Merrill Suggests XAMPP.

"FWIW, I use XAMPP for OS X. It's just as good as MAMP, but without being crippleware or a supported version."Source

Installing XAMPP was double-click and done. This is exactly the internet at goddamn idiot speeds.
Of course, once something starts to look easy, the harder it really is.