The first place to look for your bottle is definitely www.bottlebooks.com. This site has a definitive listing of bottles and values. Although some listings cost money, many of the articles and other resources are completely free.

As a comprehensive listing of other bottle collecting sites, you can’t beat www.antiquebottles.com. It has a simple layout, but a wealth of information both onsite and offsite. The best way to use it is to use the built-in search engine instead of trying to dig your way through the links, although the random clicking strategy is bound to turn up something interesting too.

The Federation of Historical Bottle Collectors at www.fohbc.com is basically a club for bottle collectors. It can be useful if you want to find a bottle expert near to you so you can take the bottle to them in person, as they have a listing of all their members sorted by location.

www.antique-bottles.net is the best bottle collecting forum, full of knowledgeable experts on bottles. If you have a question, this is where you should go to ask it – it can be very useful in situations where you’ve tried all the other resources but still not come up with an answer.

Offline, there are a few books that are invaluable to the bottle collector, notably Kovels’ Bottles Price List, which is a surprisingly cheap yet very comprehensive guide to bottle prices. There are also many books about specific kinds of bottles that go into much more detail.