Here is the sign up page where you'll begin the process:
You'll then choose your account type and be presented with three options: Personal Account, Premier Account, Business Account.
For your business, I'd choose "Business Account," select your country and hit the Continue button. You'll then go through filling in the account info (name, address, phone, etc, etc.). From there I don't remember but I think you'll provide your bank info.
If you want to get started filling out the info and you get stuck or have a question about the next step, post the question here and we'll likely be able to help.