-a all (symlinks, etc)
-r recursive
-n SIMULATION
-v verbose
--delete mirror removed files on dest
--exclude=._* remove mac hidden files such as "._DSSTORE"
rsync -arnv --delete --exclude=._* "/Path/to/files/source/" "/Path/to/files/dest/"
rsync -arv --delete --exclude=._* "/Path/to/files/source/" "/Path/to/files/dest/"