Have been asked about uploading document files to blogger. Here are some suggestions, would welcome tips from you too please.
I typically load files to my wiki rather than the blog and just include links to the wiki page. For example, see Teacher Resources on this wiki page, includes Slideshare files and PDFs that can be downloaded
Box.net allows you to upload files and create code that places a widget on your blog from which you can share files. See an example of this on Rocky's blog.
I have a preference for Slideshare. Upload a PDF to your free slideshare account. There are options for a url link to your file or copy the code and paste into your blog or wiki. You are also able to upload PowerPoints.
If you are using Keynote on the Mac just save as a PDF first.
Also recommend you save PowerPoints as PDFs too before uploading as it reduces the file size. For example, here is a link to one of my posts where I have included a PDF that has been uploaded to Slideshare. The file can be viewed from the blog or click through to Slideshare to download.
More suggestions from Allanah's Bling4yrBlog Allowing a pdf type download from the Blog
Then you could always forget about creating files on your computer and go straight to online documents. Have tagged a selection of options in My del.icio.us