Need to know how to accomplish this

Hi all,

I would like to make a blog where all the executives of our company can post and read each other’s itineraries and requests, and comment on them, etc.

The two things I need that I’m not certain how to approach is:

1. Nobody at all except registered users should be able to even load the main page (I suppose I could restrict this in my web site manager, or is there a wordpress feature?)
2. I’d like to have peoples’ pda phones use an RSS reader to pull newest posts down periodically – but again with the login required to even access any data, I’m wondering if authentication for RSS feeds even exists? I’ve never seen it in options of RSS readers.

Any help would be greatly appreciated. This project would make an amazing improvement in the administrative communication across my company’s top people.