I have a web site that I made with CoffeeCup. Looks and feels great.
What I need: I have managers who have to upload content. I guess I could tell them all to download ftp software (like CoffeeCup direct)
to upload content to client directories and control their user access via seperate logins and passwords. Without getting into too much detail, my clients need to see specific data as it relates to their company, and on our web site these links exist. Right now my managers mail the content to me and I post it to the web site via my ftp program. I want the managers to be able to go to a link on our web site that lets them upload content without using an external ftp program. How do I accomplish this?

Since CoffeeCup has no online editing programme (so-called CMS), your managers have to use some FTP client to upload their pages.

So what software should I use to accomplish this.
Please give me some specific examples if possible

You should check with your providing host, usually there are a couple of CMS programmes available in your cPanel. Mambo or Joomla seem to be the most used ones.

http://www.joomla.org/
http://source.mambo-foundation.org/

That would probably be ideal for multiple people needing to add their own content. I've been using Joomla for a bit lately and probably haven't made use of the majority of its potential. There's a lot of add-ons to help with certain needs, in your case Community Builder will probably help with multiple users & clients. It'll most likely take a bit of reading and learning, but after it's up and running, there's no software to deal with for the contributers, only logging into the site w/ their browser to add content or make changes.