I am not familiar enough with history to search for this type of information myself. Would love sources: books, sites and videos are all welcome!
Edit: Found a nice link
hi! not discouraging anyone from providing more info, but FYI, you may be interested in previous posts on mining from the FAQ (link on sidebar):
a site about vikings and bog iron
You can get to the first link through the FAQ but it's kinda hidden. The second link has lots of nice pictures and is well written for the amateur inquirer.