Some makers have sn tables on their web sites that will get you in the ball park of when a firearm was made or shipped.
You can't
You find a published list of serial numbers for the maker.
You can check with the dealer where the gun was purchased. He will need month and year of purchase.
Go the the gunshop or person you bought it from.
Look up the serial number.
Try Proofhouse.com
You find a book with serial number information and look it up. You find a book with serial number information and look it up.
Contact your local police and ask them to run the serial number.
Look on the butt or the frame.
IF YOU CAN REMOVE THE HANDLE THE SERIAL NUMBER SHOULD BE THERE. YOU CAN TAKE THE GUN TO YOUR LOCAL POLICE DEPARTMENT AND HAVE THE GUN REGISTERED OR SEE IF THEY HAVE A PROGRAM WERE THEY BUY THE GUN.
1 - find serial number on weapon 2- find book with serial number data for weapon you have.
Get the serial number Get a book on the comapany that has Serial Number data or a book that has serial number data, i.e., Blue Book of Gun Values.