misc_teleporter
1.Firstly, create a good sized room (300x300x300) and place your info_player_start and a light in there.
2.Next add the misc_teleporter entity to one end of the room. Give it a
"target" "tele1".
3.Add the misc_teleporter_dest entity to the other end of the room, and rotate it so it faces the correct way (the way you want the player to come out facing). Give it a
"targetname" "tele1".
4.Compile your map and check it out in Quake2. Here's a sample map showing the teleporter.