It's perfectly possible. However, a look at some of the regular threads on here will illustrate some of the very common pitfalls. Firstly, when you adopt, please make it clear to the rescue that a child is likely to be coming along. Many rescues will have dogs that have been fostered with children and this is a good idea, as you will know the dog has been used to a busy family environment.
Think hard about the financial aspects of dog ownership, particuarly if your family income drops after children arrive (either because of reduced working hours or increased expenditure on childcare or combo).
Think about the time and commitment involved - be prepared to consider using a dog walker when baby is very small or you are coping with out much sleep (and again, factor this into your budget).
Before the baby arrives, make sure you have worked on dog training, and dog is good on the lead, and has good dog manners (things like reasonable recall, doing a down, sit, stay, not jumping over visitors etc.) Don't leave food lying around. A well trained dog is much, much easier to live with and after the baby arrives you will be walking it with a buggy, possibly with stitches after a CS, so you need a dog that will work well with you on this. Time spent at dog training classes now will pay golden dividends later.
Set up very clear ground rules that all adults in the family will abide by - things like not feeding titbits, whether allowed on furniture, keeping doors closed, respecting dog's space and how children (your own and visiting ones) will be taught/shown how to interact with dogs. Many people find stairgates useful for keeping dogs and toddlers separate - this very much depends on the layout of your house though.
Good luck. There are many, many people on here who have successfully combined dogs and children and with a little planning it can work beautifully. Personally, I think that being brought up around animals is one of the loveliest things about childhood. Also on a positive note, DC brought up around dogs are less likely to suffer allergies and asthma. 