I've posted these links for people before, but they give great advice.
http://dogsandbabies.wordpress.com/2011/02/07/how-to-not-magnetize-your-baby-part-2/http://dogsandbabies.wordpress.com/2011/01/24/mamas-dont-let-your-babies-get-magnetized-to-dogs/http://dogsandbabies.wordpress.com/2011/02/24/helping-toddlers-not-be-magnetized-to-dogs-part-3/Honey was 3 when our first baby was born, but was very unused to children. She has adapted brilliantly (though there were some hairy moments along the way!).
My main tips would be - make sure you get Rufus used to any stuff you will be using - Honey was terrified of the pram (which wasn't a biggy for us, as I use slings to carry both children, but would be tricky to deal with if you're going to take a buggy on dog walks).
- make sure Rufus has a good "leave it" (as he will want to adopt socks, nappies etc as his!)
- make sure Rufus is used to the approximate routine you might have... so he needs to be used to you sitting on the sofa for chunks of the day not directly paying him attention (as whether you are breast or bottle feeding, you will be sat feeding for significant chunks of time) - possibly used to walks being at different times - used to you not heading straight downstairs in the morning etc
When we brought Isobel home from hospital, my OH carried the car seat in so I could greet Honey as normal.... we then did let her sniff Isobel once Isobel was on my knee. We rewarded calm interest. As Isobel grew, she was encouraged to give Honey space, to avoid Honey's bed etc. But also encouraged to give her treats (with our help) from well before she was crawling - this meant Honey gradually associated her with positive things, while Isobel learned to respect her. We did have some growls and a couple of snaps (Honey is very highly strung and has quite a complicated temperament, so I doubt this is a common experience!), which we were careful to respect - we didn't tell Honey off for growling but solved the situation for her - either encouraging Honey to move to somewhere she felt more comfortable, simply positioning ourselves between Honey and Isobel, or encouraging Isobel away, depending on the situation. Honey still has the tendency to guard the bottom of the stairs, but she is very much more relaxed with our younger daughter (nearly 4 months), so we've obviously managed something right along the way (and Isobel is besotted with Honey, but alongside a healthy respect!).
