Lego resources – brick database, lego software, community – and shop@Home – The LEGO official site and online store.

Peeron – Very useful LEGO set inventory database. Also includes pictures of nearly every single LEGO part, and also a LEGO color chart.

Bricklink – A venue for individuals and businesses from all around the world to buy and sell new, and used LEGO through fixed price and auction services.

Brickset – A nearly-complete LEGO set database.

LDraw – A CAD system designed by and for LEGO enthusiasts.

LUGNET – Global community of LEGO enthusiasts. LUGNET unites LEGO fans worldwide through discussion groups, web pages, and services. Home to thousands of LEGO fans of all ages.

BrickArms – An online store where you can buy custom weapons, weapons packs, and custom minifigs. Features a wide selection of firearms and other war accessories that fit perfectly with LEGO minifigs.