I have a Mac; I have a Blackberry. I do sync calenders and addressess but do it all through Gmail and Google Calender using Google Sync. To transfer music from my iTunes library, I use the Media Manager software available as a free download from RIM. RIM also offers a free download of Pocket Mac to manage your Blackberry on your Mac. I downloaded it but have never used it. If I want to transfer other files, I just hook my BB up to my Mac using the supplied micro usb to usb cable. The BB shows up as a removable drive.
Best of luck.
I use a mac laptop as my primary computer... although my blackberry is almost replacing it these days!
I don't do a lot of music related stuff on my blackberry outside of pandora/slacker and use it mostly for writing and editting large documents. Good thing copy and past works between memo pad and email... XD
I sync my contacts and email through google as well. It works very well for me.