I agree with Red, if its been passed down through a family member or you have had it for quite a number of years, chances are that it will be original. The owner of this forum has a book out on British coins, its called Collectors Coins GB, its only about 7 pounds and could probably get it from WH Smiths or so, that will give you weights and a guide on prices for your coins. If you have many foreign coins then i'd suggest the Krause book of world coins, its a hefty book at around 1200/1400 pages long, but it also goes by Centuries 1800-1900 1900-2000 so beware what you buy, maybe look through the most common century and purchase that book. If you have any German coins, Kaisserreich etc i have a book for that, so you're ok there.