The "Legal Research" tab contains resources to introduce yourself to legal research in general.
The "Primary sources" tab is place where you want to go if you are looking for case law and legislation.
The "Secondary sources" tab contains suggestions of publications to get a good introduction to environmental law as well as tools that might help you find more of these resources.
The "Government information" tab contains links to tools that could help you find publications from several levels of government.
The "Legal news" tab contains suggestions of blogs published by law firms and other organizations.
"ECOLEX is an information service on environmental law, operated jointly by FAO, IUCN and UNEP. Its purpose is to build capacity worldwide by providing the most comprehensive possible global source of information on environmental law ." (organization's website)