Trademarking a new business name and logo.

You can file a trademark application even before you actually use your intended mark in commerce by filing an "intent to use" application. You must declare in your application that you have a good faith or bona fide intention to use your mark in relation to the future sale of your products or services. After you actually begin using your mark, you must then file an additional "Statement of Use" before the Patent & Trademark Office will officially register your trademark.

It is in your benefit to file your trademark application as early as possible be\cause once your mark is registered, your rights in the mark are presumed to begin from the date your application was filed rather than the date the mark was officially registered.

John's answer is a good one.

I would add, however, that when you apply to federally register a trademark you must also declare that to the best of your knowledge no one else has the right to use the mark or one that is confusingly similar. While there is no statutory duty to conduct a search, many courts (and the Trademark Office) look poorly on trademark applicants who do not conduct a thorough search for similar marks before filing their application. Professional search firms can perform a good search for about $500. It would take a trademark attorney about two - three hours to assess the risk you would take by using your mark in light of the existing marks found by the search. So for $1,000 - $1,500 you could obtain an opinion on whether you can use lawfully use your mark -- an inexpensive investment that could save you much heartache and expenses latter on if you become engaged in a trademark squabble.