1. Export your contacts from Gmail to whatever filetype they allow: ascii, excel or something. Then import that data either, a) into Outlook and sync Outlook with you BB via Desktop Manager, or b) direct to the BB if that file type is syncable to the BB, some ascii file types are allowable. You may need to discover some of this for yourself, but I know it is possible.
EDIT, I remember now you have a Mac. It will still work, just not with Desktop Manager, which is not Mac compatible. Look in the Mac section here for using PocketMac or Missing sync software to interact with the Mac.
And here is the instrucitonal from google on exporting gmail contacts that you didn't find:
Exporting Gmail contacts