How Do I Trademark a Logo?
The process to trademark a logo is identical to that of a word/phrase. Only the target of the trademark is different. If your logo includes your name or slogan it will require two trademarks to protect it. One trademark is required to protect the graphic portion of the logo and one trademark is required to protect the name or slogan portion, if these are not already trademarked. Please note that you do not copyright a logo because copyrights protect the creative intellectual property such as fine arts and music.
To understand the application process read more on Logo Trademark.
Label: Trademarking a Logo, How to Trademark a Logo, Copyright Logo