To get started, you just need an email address and a board theme. Signing up is free and fairly quick. Best of all, as soon as you register, you can get started pinning.
When you design your board, you may want to consider how people search before you name it. Pick key words that describe your theme. Also, it is important to consider if you want the board to be public or private. You can create as many boards as you like, so start a new one if you have a new idea.