They are not in the compendium.
While the familiar is in active mode, you must use a move action to have the familiar move its speed. Basically you must use the relevant action to have the familiar take that action. For instance you can spend a minor action to have your familiar open a door (if it's able).
In passive mode a familiar can't be targeted or damaged. Switching modes is a minor action.
The full rules are in Arcane Power.
The only grand list of familiars that I know of is in the CB.