Really essential is proper tethers, and not just on tall bookcases. Drawers and low shelves are also very dangerous, particularly to children that are beginning to pull themselves up to stand. A friends child pulled an ikea chest of drawers on herself, luckily she was in the room and the child wasn't seriously hurt, but children have been killed by this. Fire guards if you have a fire, obviously.
Definitely get a TV tether. Many a child has been seriously injured by a flatscreen falling on them.
Stair gates, because you can't watch them all the time. Some people do without them, and I could have done with my sensible eldest. The small one is a bloody menace though 
We don't let them in the kitchen at all, in our case it's just simpler to gate off the door. Again, I could watch them every moment, and say no, etc etc, but I don't have eyes in the back of my head and on 4 hours sleep it's better for me to have a gate up. The eldest did as he was told, the youngest gets a gleeful expression and starts throwing things out of the cupboard if she's told no
. As they get older the gate will come off.
Tie up blind cords, and make sure there are no long loops on bags etc that they can get caught in.
Those door foam things are useful, children love to play around with doors
and they help prevent broken fingers and lost nails.