From PHPKitchen today:

And now for the standard "installing PHP from scratch" tuturial, no website would be complete without it. In fact, when I did this last week I had to search around for ages for the various information, so here follows a step-by-step list that aims to save you the hassle. Lines starting with a # denote comments, everything else must be typed as it appears.

True to the title, he goes through every step of the way, commands and all, to get a setup of MySQL, Apache, and PHP (LAMP) set up on your machine. Of course, there's no "gotchas" to look out for, but then he also just compiles PHP with the base amount of modules (just MySQL), which is where a lot of the confusion lies...