Alt + Arrow key - Switch between targets. I think be default left and right are inversed, so you might want to hunt them down and change it, if this bugs you, like it did me.
Function key (F1, F2, etc.) - Use High slot items
Alt + Function key - Use mid slot items
Ctrl + Function key - Use low slot items
Double click - Move ship in that direction. Good for if you are trying to approach a large amount of things, but don't want to take the time to pickout the center most object.
Tab - Minimize all windows. Useful if you are being targeted/attacked, but can't tell which direction it's coming from.
Alt + M1 (left click) - Center cameras on an object. This is useful in both PvP, if you are trying to identify specific ship fittings, or Mining Ops so two characters don't both mine the same rock. Note: this can get a little glitchy if you continually switch back and forth between alt+M1 on objects in the overview pane and alt+M1 in space, so try to stick with one or the other.