User Area Content Question

I’ve recently started brainstorming with my coworkers about rebuilding our company’s website. I’m pretty familiar with WP and very familiar with CSS but when an idea came up that I wasn’t sure could be accomplished within the WP CMS I came running to the forums.

The Feature: We’d like to set up a “Client Login” area on our site using the user setup of WP. Once logged in we’d like each client to be directed to a page specifically created for them, that we can add content to for them to download. We’d also like to ensure other clients cannot view each others areas.

By doing this we could make things available on a client by client basis for them to download. Instead of trying to email or yousendit a 50 megabyte file to a client, we could upload it via ftp, toss a link on their page, and let them download it directly.

I have no clue how I could even start developing this. Any suggestions, even just concept-wise?

Thanks in advance!