If you are hoping to reuse a lot of existing classes and functions then this tute may be just what you are after phpfreaks.com
If you don't need to worry about that then there are other options that are more flexible and perform better than odbc. Tell them to to replace access with sqlserver 5 express edition is the first one. It's free and a far better backend for a web app. But I bet that's not an option.
You will have to check with the host, but they should have included the references for OLE automation in Access. Then you can use COM to work with the acces db in php. There is an example of the connection script you'll need here . Be sure to read the user notes at the bottom as there are lots of tips to ease your way.
You'll need to learn the differences in acess's dialect of sql - very non-standard.
If yours is a complex app then it will pay to learn vba. With access you can define your own functions to call in queries. These functions can be as complex as you like, amounting to t-sql stored procedures and triggers. You will also find a host of inbuilt functions for use in queries to manipulate and transform data for both presentation and storage. Most of the complex query types are fully supported, more so than in mysql. But jet is such a pig of an engine that you will find it pays to break complex queries down into several simple query tasks using work tables, you can easily improve processing times by an order of magnitude doing it that way.
Oh yes, both individual queries and groups of queries in a procedure can be made transaction-safe. Except that access tables and mdb files are never safe so make sure you have excellent backup and recovery procedures in place for when they do screw up.
