Hi
Can I qualify this by saying I have limited experience of CODM on mac's. However in general I'm pretty sure there isn't much to say, it's just the same as windows really. If you can use a mac and cope with the keyboard layout you will find it virtually identical!
I did the first one using the inbuilt TextEdit software which got the job done. I believe that oxygen xml editor (non free) works very well.
regards
Tim