Simply setting up a wordpress blog on a good domain name and decent hosting, and starting to blog about what you want to accomplish will get you started.
Ideas for posts--
How is promoting a music site different than other sites?
Niche marketing for music sites
Monetizing a music site
Using adwords to promote a music site
You get my drift, I'm sure. Geez, just doing this sort of thing once a week or so, and then adding features as it gets rolling, and as you know more about what direction it seems to be going based on response, keyphrases used to find you, pages that are linked to, etc . . .
Keep in mind too that there are many different genres of music. It's obvious you like hip hop, but Celtic Traditional is hot here in the States, for example, and that's really a different sort of music from hip hop. Are the skills and approaches the same? Probably, but maybe not. Just doing the research on the differences for each type of music, and writing up the blogposts could keep you busy for a long, long time.
