There are many ways to use Canon DSLR footage in FCP ranging from native file editing, transcoding with Compressor to plugins. In fact there are people out there selling tutorials on how to do it! Download the official workflow white papers from Canon to get it right and maybe save some time and money.
Canon have very kindly published a whole range of white papers on the usage of DSLR & XF300/305 footage within the top 4 editing apps. Take your pick from Premiere, Final Cut Pro, Avid and Grass Valley Edius. I do hope this will stop the constant stream of posts on forums asking why their NLE slows down when using H264 files.
Don't forget we posted this article about FCP v Premiere with Canon DSLR footage. Also don't hold me responsible for the odd edged box cutouts on the banner - they are from Canon!