I use XAMPP as a local test server on my Mac for testing and debugging. I mean, nothing is more embarrassing than making file changes to a live site and bringing it down. One thing always bothered me, but not to the point of solving it. WordPress, Drupal, and other CMS software provide built in automatic updates or installation - but out of the box it does not work on XAMPP. It's a simple fix, just first hunt down your httpd.conf
Watching file sizes and following coding standards are only one simple way to optimize your website. Proper HTML will ensure you page is processed as smoothly as possible, but does not mean a major speed boost. When the dust settles from developing a new website, I turn to Google's PageSpeed for the round up of last minute tweaks. PageSpeed alerts you to multiple tips and tricks to help edge off a few milliseconds of your page load - which has become crucial.
The easiest way to learn PHP is to be able to create and edit code and see instant results. When I was younger and learning I couldn't afford to have my own web server so I installed a WAMP environment - I also didn't have a spare machine laying around to toss Linux on. Unfortunately I never heard of EasyPHP until a bit ago, it was originally released in 1999, but you can Wikipedia that.