We worked with our trainer to get ready before she got here. He wrote this great article for the Huffington Post about just this very topic....which gives you most of the tips and tricks that you'd expect. Together we also had to admit that he needed a little Prozac help just to get him closer to being ready. For him Prozac is not a magic pill, but it does help take the edge off so that he can more easily deal with new ideas and new people.
But honestly the thing that I think has helped us THE MOST is that starting when Fiona was only about a month old, we started putting treats in her hand and had her "give the dog a treat." We made our Boston lay down and then take the treat very gently. And once he got his treat, she'd get to "pet the dog" very gently. We repeated this each day.
Now he pretty much ONLY gets treats from Fiona each day and never from us, and it's become something that she loves to do now that she's old enough to notice the dog. And the best part is that the dog has gotten SOOOOO much more comfortable being around her. Obviously we're always paying attention and supervising their interaction, but I'm no longer filled with the same worry as before.