Wizard based Content Manager help

Hi, Im currently working on a Content Manager. The way we wish to add new content is throught a wizard with about 5-7 steps. I was wondering if anybody could suggest some methods that would be best for what I am trying to do. The main issue for example, is if a user is adding new content and they are at step 5, and want to go back to step 2. How could I get it to store the data inputed on steps 3,4 etc. Session Vars? Hidden form text fields? Any help gratly appreciated. John Harding