Hi,
principle is the same but ReDJ is a little bit more flexible to manage compared to .htaccess, expecially when you have a lot of redirect to implement. And not all the users have possibility to manage .htaccess file.
About documentation, as soon as I'll release ReDJ 2.0, there will be a good tutorial to start using ReDJ. But for a basic usage, is not so difficult as it seems.
You just need do add into component items for redirect you need. Plugin will do the work for you (so, it must be enabled). Also, it is better to put the plugin as the first one between system plugins, to avoid conflict with other redirection extensions.
These are some examples of how to configure items:
www.sistemistica.it/forum/11-redj-in-english/313-redj-donat-work-.html
www.sistemistica.it/forum/11-redj-in-english/377-my-main-link-in-google-doesnt-work-now.html
www.sistemistica.it/forum/11-redj-in-english/265-redj-not-working-any-idea-.html
Let me know,
Luigi