I created a database of basic design papers, excels, PDFs, etc that I have collected.
There isn't much there yet, but it is a starting point. If you have helpful stuff that you'd like put up, please send it my way.
DISCLAIMER: I found all the files I've put up in simple searches. Therefor, I am assuming the author(s) wanted them to be available. If you had a hand in any of the documents and want them taken down, just let me know.