Are you trying to syndicate other bloggers' posts on your site? One way to do that would be to periodically retrieve their RSS files (which are XML files) and transform them to HTML. XSLT works pretty well for this, but the learning curve is very, very steep.
In case you haven't run across it yet, Mark Pilgrim's article on RSS for XML.com is pretty good.
The Utah State government site (!!) of all places has a good resource page on RSS. Their former CTO, Phil Windley, used to be an exec at Excite and is pretty big into blogging. That page has a fairly extensive section on creating RSS feeds.