There are some user import addons:
http://www.concrete5.org/marketplace/addons/all-in-the-advanced-use...
http://www.concrete5.org/marketplace/addons/lerteco-user-importer-p...

To export, you can use the export link from the user list in the dashboard.

You could also try a cut and paste to excel from the table output of the user list addon:
http://www.concrete5.org/marketplace/addons/enhanced-user-list/...

Or write a custom view for the addon that was more suited to exporting.

Thank You... This helps A lot.

Where can I download a CSV for my old users that includes a password field?

The "Export All" link in my old site does not include the password field.

The password won't work on the new site because the new site will have a newly generated seed. The best way to handle that is with something like bounce box
http://www.concrete5.org/marketplace/addons/bouce-box/...
Showing a message telling users to go through the new password procedure.

Passwords in C5 are stored encrypted. So if you want to avoid the above, you could try and hack the list output to show the encrypted password, hack the new site to use the same seed as the old site, and hack the importer to read and save the password without further encrypting. This is not something I have tried, so may be a dead end that can't be made to work.