Mac os snow leopard reinstall panic!

Oh no!

Last night my brand new iMac stopped working when I tried to migrate a second user to it. I got a flashing circle/cross, a hard drive question mark and the apple logo. Trouble.

When I talked to apple tech support this morning they said to reinstall the os and it would not erase my data. Did that, but now none of my users show up.

In the hard drive, under users there is just a new dummy user from my reinstall, but the real users, and data, are sitting in a folder named users, with a long number after it. Applications and library and system look the same, with duplicate folders with long numbers after them.

How do I get my users back! Can I just drag them (and library, and applications) into their new folders, or will that just mess things up?

I'm panicking, as in the transfer over I lost my backup of the first mac I successfully migrated over. Don't want to do anying that would lose my iTunes etc.