I am a total noob at this, and am trying to teach myself. But failing.

I installed phpNuke through fantastico and it created the mysql databases, but for what ever reason I still 404 at my site, and it created no new files. I really don't know what I'm doing wrong, maybe someone could just give me a run through on how to install phpNuke through fantastico, or manually. Anything to get me past these 404 errors I'm getting.

Thanks.