Just follow the instructions in the checklist, have your fingerprints taken by a professional (preferred but not necessary) and make sure you fill and sign all the required forms. Below is a link for a more active thread for people waiting for their FBI reports. It takes about 4 months these days, so I suggest you send the request then forget about it for a while, otherwise you'd go mad waiting!
http://www.canadavisa.com/canada-immigration-discussion-board/fbi-pcc-t247817.3465.html