I would look into creating a simple SQLite database (it doesn't have to be SQLite). It's fairly easy to maintain and with the advent of new tools, you do not even have to know SQL to use it. Search for SQL Mac online and you will find tons of helpful articles. My pick is MySQL (for personal use) and my preferred IDE is SequalPro (free).
By the way, I'm sure many will suggest apps like Bento or FMP (File Maker Pro) but you should be able to get by just fine with a database of your own. Lots of helpful information on the web (youtube is always a good resource as well).