From “The Essential Secrets of Songwriting” website:
There’s something to be said for publishing your own music. Doing so is easier than you might think. It requires very little financial outlay to get it set up. It usually means setting up what’s termed a “sole proprietorship” – an unincorporated company. They’re quite easy to set up, and is usually done through provincial or state offices. Simply do a search online for “sole proprietorship” and your country. There is likely a small administrative fee for this.
The advantage of publishing your own music using your own company is that you retain the copyright. Anyone wanting to sing or record your music has to go through you, not an outside agency.
The disadvantage to trying to do this on your own is that the distribution of music is time-consuming and complicated. Letting other singers know of your music is not easy task. Large publishing companies usually have long-established lines of communication. Getting the message out there of the existence of your music is better done by the large companies. But publishing companies traditionally take a large royalty fee, so you have to weigh the advantages of a much larger potential audience with a smaller payoff.
If your immediate plan is to sing the songs yourself, you might want to try self-publishing as a starting point. Using the internet is a good way to market your music. The advantage is when another singer hears your music and wants to record it. You retain copyright, so a singer pays performance and mechanical royalties to your company.
If you want to research the setting up of a sole proprietorship, here are good websites with applicable information:
Canada: Business Registration
United States: USA Today: Strategies: Here’s How to Set Up a Business
United Kingdom: ByteStart