Fill it up half way in the garage, watch for a few hours check leaks, fill it up more (repeat), check the stand if its wood, make sure its not rotting and looks stable. After ~24hrs, if no leaks are present and no cracks or damage found. I would gently clean it w/ tap water and a rag, rinse, repeat (could use a LITTLE bit of bleach, but RINSE it REALLY GOOD afterwards). I would then move it to its final destination.
Equipment, check to make sure its all working, obviously you will know about the heater after you ran it for a little. (stuff is pretty cheap ~$40)
Filters I would probably replace the media w/ new. Clean the housing with tap water.
(Don't know how well that other person took care of the tank, and media) Best to just start fresh and new.