PHP? ASP? Suggestions?

Hey guys. I’m doing a website for a client right now, and I’m thinking about tackling my first database driven website.
It’s for a toy store, so they have a large inventory, and I think it would save a lot of time to have web pages built dynamically by php or similar language.

My question is, what should I learn?

Here are my limitations:

  1. Currently, the server is running Apache/1.3.27 (Unix) FrontPage/5.0.2.2510

2)I don’t know what the server has installed in terms of database capability, etc.

3)I’d like to do an access database, so the store can do some of the upkeep of inventory, rather than doing it in MySQL or something.

Is php the way to go, because it’s a UNIX machine? Is the access database a pipe dream, and i should go with a SQL database? Do you have any handy tutorials, book recommendations?

Thanks for all your continued help and brilliance,

–EP