Module development and code questions

I am trying to figure out how to write a module that will allow administrators to create sub-sites. These sub-sites will be part of the main site, but still have their own mini community. In other words, what I want is to have mainsite.com/subsite_name go to a sub-site page with maybe a news page, about page, forums link, etc. The news page will show blog posts from owners of the sub-site. The other pages will have somewhat static content that should be editable by the sub-site owners. It seems like Drupal is certainly capable of doing this already, so I am not entirely sure if a module is necessary, but it seems as though some of the relationships with the other modules will at least need an additional database table (i.e. associating a forum with a sub-site), not to mention how this should be integrated from the administrative side (i.e. automatically creating a forum when a sub-site is added).

Currently, I keep going around in circles with how to handle the news page. It seems like sub-site owners should be given a pulldown menu in their blog creation page that allows them to choose which of the sub-sites that they own (if any) that they want to publish the content on. Then, on the news page, I suppose I could just display the nodes that the owners of the site-site marked as wanting to be displayed on the sub-site. However, then I have to deal with all of the logic of listing the nodes (i.e. handling overflow, comments system, RSS, etc). Maybe there is just a simple node API of displaying desired nodes and allowing Drupal to handle the rest of the logic (i.e. so comments still work, and so I could go to mainsite.com/sitesite_name/rss and get a feed of the news feeds for that sub-site).

If I discover some information during the authentication process that I want to associate with a user for the duration of their session, is there any means of doing this? From the hook_auth funtion, I don't have any idea which user it is that was authenticated, but the remote authentication server sends session data that I want to keep with the $user for later use. I could place this data in $_SESSION, but at what point would it be appropriate to assign it back to the authenticated $user? hook_user('login'...)?

Just a friendly warning, do not use updates (and I am told manager) as a module names.
These are special names in Apache and the module will not work if you have clean url's turned on (you get a Page forbiden message).

I found this out after developing a module called updates on a win server and then installing on the real site.
Three cheers for search and replace :).

I have the RSVP module installed.

For some reason, whether its needed or not, the rsvp.css file is always included at the head of every page.

Its a small file, but the bandwidth can add up, and its unnecessarily being called when rsvp's arent being used.

Am I mistaken somehow?

If i'm right, is there an easy way to fix it?

For example, a 3-day conference. Can this be done with the Events module? I would like my calendar to display a block of a "weekend event" in a certain color, and that color be associated with a particular node.

Thanks!

I keep going over and over the Handbooks Module Guide's explaination of the node building mechanism. Nothing seems to match anything in the present Drupal system.