From Paul Graham’s How to Start a Startup:
You need three things to create a successful startup: to start with good people, to make something customers actually want, and to spend as little money as possible. Most startups that fail do it because they fail at one of these. A startup that does all three will probably succeed.
Where to find ideas:
If you want ideas for startups, one of the most valuable things you could do is find a middle-sized non-technology company and spend a couple weeks just watching what they do with computers. Most good hackers have no more idea of the horrors perpetrated in these places than rich Americans do of what goes on in Brazilian slums.
Amusing:
There is more to setting up a company than incorporating it, of course: insurance, business license, unemployment compensation, various things with the IRS. I’m not even sure what the list is, because we, ah, skipped all that. When we got real funding near the end of 1996, we hired a great CFO, who fixed everything retroactively. It turns out that no one comes and arrests you if you don’t do everything you’re supposed to when starting a company. And a good thing too, or a lot of startups would never get started