I get into the why a little more in this video, but basically, this will show you how to post a blog post in XLsuite and included a file that you want people to download.
You put the file in your file manager, create your blog post and link to the file in your file manager.
Easy :)
Have a look
http://xlsuite.com/blogs/training/2009/3/06/publising-a-download-link-in-your-blog/7864