This is a non-copyrighted book I found today and covers all the good stuff in non-technical terms <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' /> covers a good range of data from spark test, what each element is used for. Good stuff not only for blades but guards, fittings, pins, etc..
I know this is very old but I tried the link listed and it was broken. I did a little research and found it here: