[mstefff]

If you're talking about a database in terms of a web application or something similar, it's very simple. I remember I learned my way around MySQL in a matter of days. Check out w3schools.com and go over the quick MySQL tutorial.

[jackowayed]

>I have a business idea, which will require a non-trivial database.

Non-trivial. So that's almost certainly not a relation db. Probably something really scalable like Tokyo Cabinet or Berkeley DB.