Here are links to some places on the web I like to visit - for a variety of reasons. The locators are good ones, not too much junk on the pages and good information to find the flea markets, swap meets and thrift stores.
Silver Marks, Hallmarks, Maker's Marks, Copper
Lot's of great info here, pricing, marks and thier dates, history, sale items and a friendly site admin that does not mind the occasional appraisal question.
label resource A-Z
Trademark Search / RN Search / WPL Search