I have final cut pro and a canon xh a1 and shoot all my footage either 24f or 30f. Which is the best import codec to use to get the best quality and overall results. I have been using the HDV 1080p24 or HDV 1080p30. Should I be using the apple ProRes or Apple ProRes 422 (HQ). Which preset is the best one?

I suggest you go to the Apple Discussion board for FCP and search for "HDV ProRes" and read the many informative threads. In fact, here's the link (http://discussions.apple.com/search.jspa?objID=f939&search=Go&q=HDV+ProRes). Regular poster 'Studio X' puts it simply: Capture HDV, set the sequence renderer to ProRes.

One post I would like to quote is from Zak Ray:
ProRes does not make your HDV footage look any better than it if it was just HDV. The only advantages lie in ease of editing (Google "I-frames") and increased quality while color grading / adding graphics/ compositing. If you don't need these advantages, you don't need ProRes.

Another good post here from Jason Livingston (http://www.dvinfo.net/conf/958088-post7.html).