Hello!
This is how I started, but there are many ways.
1. Start with something that interests you, say cupcakes for example.Than search for boards that feature cupcakes and follow those boards or repin their items. This gets you noticed and gives you ideas for boards.
2. I am on pinterest under the name Erin McKenzie.
3. There is a LOT of debate about using pinterest for promotion. I'm still undecided on the issue.