You mention that you are using MS Access to do this in. So you have 2 learning curves on your plate: how to use Access and how to design a relational database.

Access is the front end to the MS Jet database engine. It doesn't do a very good job of teaching you how to design relational databases.

Second, you mention that this is going to be a web-based application. I strongly recommend that you NOT use MS Access for this application. It is not designed for multi-user / multi-threaded usage.

To better understand relational database design, install MySQL client and server (it's free) and any decent host nowadays has it already installed.

Then get yourself a good book on relational database design. In other posts I've mentioned 3 that I use on a regular basis: 'Database Design for Mere Mortals' by Michael Hernandez; 'SQL Queries for Mere Mortals' by the same author; 'MySQL' by Paul DuBois.