Here are some useful tips on how to introduce dogs in the home. The best way to introduce dogs depends on each dog you are dealing with - and that first impression is important!
Be sure to reinforce both/all dogs for calm, appropriate behavior in each others presence. Your reinforcers should be calming: treats, massage, and verbal praise are good choices; tug and fetch are not. You can use tethers, if necessary, to create calm, and follow Norwegian dog trainer Turid Rugaas suggestions to have dogs approach each other in a curving line rather than directly, allowing them to sniff the ground and do other displacement and appeasement behaviors such as looking away, as they choose.