Does anyone have any tips on introducing a new dog into a household?

[Rachel]

We currently have a lab (almost 6 years old) who is great with other dogs. He's not the problem. On Monday night we picked up our new pomeranian (10 months old). On Tuesday we started introducing them. They were great together, no signs of agression, absolutely no problems. Today, the pomeranian started nipping at him, for no reason. He isn't being rough (if we think that he's about to accidentally step on her or something like that, we scoop her up quickly) She would be sitting on my sister's lap and the lab would just walk by and she would nip at him. He doesn't retaliate. She isn't spayed yet (we have the appointment set up), if that makes a difference. Does anyone have any suggestions?
We aren't encouraging her behavior. Every time she has nipped we have said "No" firmly and put her in her pen. I was wondering if there is anything else we can be doing.

 

[Stephanie]

cesar millan has a great video in his mastering leadership series on how to do it step by step, there are so many things that he talks about that are great..showing them where they are allowed , not letting them run all over the house when they get there, setting boundaries from the beginning was the most important I think.

 

[Jenny]

A lil punishment my pup trys 2 play with older dog a lil rougher say no just like a kid if it persists then after no put the offender in the cage for 5 10 min time out after a couple times the no will work . now when i say no my pup goes to his cage and lays down

 

[Aduial]

Don't spoil the pom. She's being a bully and you're encouraging it. You need to time her out when she nips at your lab. No exceptions.