User Management Plugins

Can someone poitn me in the right direction for really good user managment plugins.

I want to be able to give certain users certain abilies.

I dont want them to be able to write a post, edit s post, write a page, edit a page. I dont want ANY of my users to do anything but submit forms. After they submit it, I want my users to have the ability to view the form they subbmitted.