Enabling subscribers to add info to site area


I’m hoping for some help in allowing subscribers to my site access info areas that they can add to while viewing online.

Currently the areas that i’d like for them to have access to are in a dreamweaver templated format with 5 cells of data that they would be inputting eventually.

Is there a database format that i should be looking to? or can this be done possibly with Flash, PHP logins and external text files?

Not sure where to begin, so any help or advice is welcomed.