There are several ways to search for information.  Your results though, will probably turn up thousands, or at at least hundreds of choices.  To narrow your search, be specific  and surround your statement with quotes such as "coins issued in the 1940's."  If you want to see photographs, add that to your search. 

You can search by date, era, style, subject, manufacturer, designer, and object.

Decide you what information you want to keep and save the website or at  least the web address and information you need. 

Use the photographs you have taken of your treasure to compare to the images you find.

If you come across the monetary value of a similar object, understand that yours may or may not be worth the same.  Remember:  the condition of  your treasure  is of great importance in determining the value. Sometimes if the object is truly rare, then the quality, though very important can be secondary.  More about this later..

Many Libraries are now on line and you can search for the books/DVD you need and then locate them at your local library.  If you local library does not have a copy of the book or DVD you need, ask the Librarian to get you a copy.  This is a common feature in most libraries.

Booksellers are a wonderful source when researching possible rare or special old books.