Prepare the necessary materials. It's more than just a name you'll be registering--it's your whole concept and model for your business. You'll need to provide a clear representation of what you want to register.
[4] If you want to have a word, slogan, design, or combination of these things trademarked, you'll have to be able to provide a "basis" for filing, which is essentially an argument for why a trademark is necessary for your business.