To trademark a logo, first make sure your new logo or logos are not deceptively similar to other trademarks or another companies logo design, slogan and / or mark.
If your logo is very similar to another trademarked logo, make changes and modify the logo design before seeking a trademark.
A trademarking lawyer should then review your design and ensure that your trademark logo does not infringe upon other trademarked logos.
Your trademark attorney can then advise you on whether it is safe to move forward with your plan to register the company name and logo design as a trademark.
The links to the left and right can provide trademark forms and services such as counseling on how to trademark a logo, registering a company name as a trademark, the cost to register a trademark and the drafting of your trademark application.