“I want to code the site using PHP and a bit of Javascript, but my skills with these are not exactly up to the job yet.”
You must understand that you need to learn 2 separate things and you need to learn them well.
For javascript on the client you need nothing other than the browser you already have and the Rhino book:
http://www.amazon.com/JavaScript-Definitive-Guide-David-Flan…
Learn what’s in this book! Go through all the exercises and tutorials. Build something. You can augment the book with tutorials you find on-line. Then you can View Source on any web page and understand what they did (and what they did wrong).
On the server you will have to find any common LAMP stack and load in onto your machine. The execises and tutorials for php, MySQL, and apache should be enough, although you can find more almost anywhere. Build something! Now that you already know javascript, you can include that in the pages you build as required.
Only after you have a solid understanding of the basics of these 2 technologies should you consider a framework. This can be tricky. If you adopt a framework too soon, you may run into a problem for which you don’t understand enough about what’s going on under the hood because you never learned it. If you adopt a framework too late, you’ll be hand coding everything and will never get done.
Most importantly: you can only learn any of this by doing. Time consuming doing. Books and resources any necessary but hardly sufficient.
Do not fall into the trap of only learning at the surface and expecting to find someone else to do the coding. This does not work for a small software start-up. You must dig deep and learn well.