Based on your previous question, you probably want to look into interaction design first. Because a database users find frustrating isn't going to be used.
Yes you want a database. But you don't just want to slap up a database, it has to be designed with users in mind. And -- despite protestations to the contrary -- databases regularly suit only the team that built it.
To explain what I mean, check out
Liveplasma. Liveplasma displays music and movie search results with linkages and groupings, making an excellent interface for exploring (shopping for) music and movies. What you do not want is something so excruciatingly technology-centric only the development team who built it could love it.
Finally, you don't stand much chance without understanding 1)The business you wish to enter. 2)Competitive challenges. 3)The technology available to you (your users) and logistics. Many companies operate in a competitive vacuum, only to find out their customers don't.