I'm replacing an outlet in my bedroom, and as soon as I opened it up I noticed there is the normal bare ground wire, two pairs of wires going into a backstab outlet, and then a single wire connected by screw. This is not connected to any switch or light or anything. The new outlet is not a backstab, got it from Wal-Mart. My question is, how should I hook this up? I'm assuming i can't connect two wires to one screw. Also there are three white wires and two black, one of the three white wires is the one on the side. Thabks for any help.
You should use either side-screws, or backstabs, but not both at once. And you should never use backstabs, according to many of us! I just had to deal with a broken switch where the backstab was the core cause.
If you really need to connect 3 wires, you can pigtail.
Or, consider the $3 "screw-and-clamp" types such as Leviton that are sold at home-improvement stores and electrical supply. They look like backstabs except the holes are directly aligned with the screws. Aside from using the screws the normal way, you can screw down to clamp 1 or 2 wires in the holes behind the screw. So with two screws, you can connect up to 4 wires per side.