How you start with the introductions, depends on how much interaction the dogs have had before you bring the new dog home. However, if you are just starting to introduce them, I would recommend it be on neutral grounds. One way I like to introduce dogs is by parallel walking them together. I have two people, and each person has one dog. Obedience is thrown out the window. You begin approximately 10 feet apart, and walk and talk normally like you would if you were having a neutral conversation. You might have to do this for approximately 30 minutes, but once you feel the energy from both dogs has lessened, or they seem to be more indifferent about each other, you walk closer together without stopping. Keep walking; you continue to keep growing closer together until both dogs can sniff or walk next to each other. Once you feel both dogs are somewhat comfortable is when you allow the leashes to be dropped or head home and do the same thing in your backyard, then drop the leashes and allow the dogs to sniff each other. Make sure there are no bones or toys around either dog. Never force the interaction. Be patient.
Once the dogs have been introduced, allow the older dog to go in the home first by telling the dog to sit, then releasing the dog into the house. Allow the new dog to come into the home. Make sure there are no toys or bones laying around. The dogs should then be allowed to sniff your house under your supervision.
Do not feed the dogs together at first. Make sure they are fed separately for at least two weeks. With regards to sleeping arrangements, have the new dog stay in his own area. Make sure to spend time with each dog individually, as well as, doing fun things together, which will provide a positive association toward each other....."fun things happen when we're together, I like being with you"!