How do I start?
Using Jamroom
If it were ME (and my idea might not be the best plan for YOU) and i only had an old 2.0 outdated archive and a new 3.0 with no archive, I'd start over completely fresh with a setting up a new site with the features and categories all in place.
Once the new site was 'mostly' set up and functional, I'd start inviting everyone from my 3.0 to join the new site fresh. It might still lack a few refinements and functions, but that's ok. Then I'd run both for a month and suggest that during that time the members themselves pull whatever content they want to save over and post it to the new site. (they should be made to understand that they won't be able to merely point links to stuff in the old site, as that site will be taken down)
Meanwhile, I'd stimulate the new site with interesting new topics or a contest etc. And a forum or group called "Suggestion Box". Make them use the NEW site to post their talk about the new site and what it might need...not the old site. (this will help get them used to posting in the new site, even if it's mostly to gripe...sneaky!) Their posted gripes will actually be part of the growing process and will stimulate constructive activity and the sense of member inclusion. Just the act of someone joing and logging in and uploading their new profile image will be exciting for them and make it less of a dreaded unknown.
Once that 'tandem sites' time was up for members to copy content over that they want to save, I'd then disable the features on the ning site so members can no longer post NEW content for some features, and I'd close the old site to not accept new members, and add a big pointer on the home page directing new people to the NEW site instead to join. After another shorter period of time, I'd finally put the old site in 'frozen' maintenance mode with a screen message directing to the new site. After maybe a month of that maintenance mode (to catch people still stumbling over there through google links) I'd delete the old site and kiss Ning goodbye forever.
I have to remind myself that getting my new JR site 'just right' is going to be an ongoing process, so I need to keep my perfectionism tendencies in check. I realized that once my members start logging in there LIVE, they are going to be bringing up all kinds of things i may not have noticed or had a chance to tweak or fix yet. It's almost impossible for me to test enough in advance to catch and fix the hundreds of things that live members will notice. I plan to enlist their help in spotting problems and suggesting improvements- people tend to like to feel part of the process. Then I'll keep a notebook of the stuff I need to keep changing and I'll just work on one thing at a time. Otherwise I'd go crazy and be way too discouraged. As the weeks go by the members will see that you are improving things slowly and steadily, and I suspect they'll be excited to be part of that process.
I am going to be importing my fresh 2.0 archive, but that's because I am still on my 2.0. But I'll be using a lot of the rest of what I describe to prepare my members for the transition from Ning to JR, knowing that members usually detest change.
This is all just my own two cents, without even really knowing your site- so use what might be good for you and just throw the rest of it away if it doesn't appeal or apply to you and your situation.
