If you want to learn about databases, then you need to start working with one. Excel is a spreadsheet application, which can be used to maintain lists, but is not really a database engine.

Microsoft Access is the front end to the JET database engine, so you already have a head start on the front-end part. You will need to learn how to use Access to design and manipulate your data.

The other question you need to answer is whether to have it web-based or not. Why do need it to be web-based? If this is crucial, then you have 2 learning curves. One for designing the database, and another for learning a programming language to build your front end.

If you are only interested in learning about relational databases, first get yourself a good book. I recommend 'Database Design For Mere Mortals' by Michael J. Hernandez.