I lost my HD and reformatted and am starting from scratch. My mapsource came with a handheld we bought a few years ago. I had been keeping it updated thru Garmin and was the latest version I think. But there was some lengthy procedure to install this if I recall. I have 2 discs from the handheld. Mapsource City Select V 3.00, and Trip and Waypoint Manager V 2.02. There's also some unlock code I recall messing around with. Is it still the same code even though I'm installing it again. Do you need to unlock, and/or reregister w/Garmin? Am I entitled to a new Version of Mapsource since I bought my Zumo less than a year ago? Anything else you can tell me about this would be helpful. I have the disc that came with my Zumo, still unopened. It's City Navigator NT, North America. Should I be using that instead? Where do you get the unlock code? You can tell I'm a little lost with this stuff. What should I be installing/doing to get back up to speed here? Thanks gang! 
Hoist! 
Howie, haven't done this myself in quite a while but I can tell you that you want to use the City Navigator NT, North American with you Zumo. Probably version '2008' judging from when you bought your Zumo. There is a newer version out and yes, I think you are entitled to it free of charge as you stated. City Nav may not work on your handheld, no idea, but know for sure that is what you want for your Zumo.
Think you should have the unlock code on seperate paper somewhere in the stack of stuff you got with the Zumo. But if all else fails when you get there I'd call Garmin tech support. Hard to reach sometimes but they've always been great when I had a question or problem.
Hope this helps a little.
Jerry