Reddit mentions of Core Web Application Development with PHP and MySQL

Nothing wrong with piggybacking! Us coders know how pointless it is to reinvent the wheel (but that doesn't stop our egos from trying, though :p). I think your plan is a great way to approach the project. Get something truly solid working first, then step it up from there.

Since you mentioned you are interested in programming (high five!), there are a couple of books that I can mention that are good for beginners:

The Head First series are great because they explain programming in a very direct and simple language and are example driven.

There is a web site called CSS Zen Garden which demonstrates the true power of Cascading Style Sheets. This website offers users strictly content (text) and then demonstrates the incredibly different ways programmers have styled the content using only CSS. Pretty cool. The Missing Manual series is also nice to have because they do a great job of simplifying advanced concepts and are a nice go-to guide when you are forgetting something that you KNOW is really simple...

Since you mention PHP (vs. ASP.NET), a great PHP book that combines with the MySQL database (yes, you will have to learn databases at some point. I apologize in advance) is Core Web Application Development with PHP and MySQL. It is a no frills reference and finishes off with advanced projects that may help you towards your end goals.

And if you are a learner who likes clear cut, non-cutesy text, the O'Reilly series are pretty much up your alley. (They are the texts with a white cover with an animal of some sort. You'll know it when you see it.)

Commence information overload. Welcome to a programmers life. :)