UNESCO

It may be surprising to find this organization here, but the UNESCO site provides useful information on the Galapagos archipelago in particular, as it is part of the UNESCO World Heritage list. Maps, descriptions, photos are available online, totally free of course. It is a very good way to have an overview of the destination before departure in addition to all the information that you will not fail to glean on the Net. The information on the site is constantly updated and is very relevant.