A great site for previewing ship builds.
Thrudd's Trading Tool
Another useful site for checking prices, and working out where to trade.
The offical community fansite
The official community fansite.
A very useful site for finding other third party tools/sites.
Elite Dangerous PvE (Mobius)
If youre not a fan of PvP, and do not want to fight other people; then mobius might be for you. Mobius is a dedicated PvE group with no PvP allowed.