If you're a city dweller who relies on subways, buses, and cabs, you'll need a lightweight but sturdy stroller that folds quickly and is compact. A car seat carrier frame would work well, or a light, basic travel system. A sturdier stroller, perhaps one with larger tires, may be easier to push if you'll be going for long walks. But a bigger, heavier stroller might be harder to lift and fit into your car trunk, or to use on public transportation.
Some traditional and all-terrain strollers may have better shock-absorption, a three wheel configuration, and a seat that gives your baby more support than a simple umbrella stroller. This is also true of jogging strollers, but there's no reason to buy a jogger unless you're going to run with it. If you'll be tromping through snow or on unpaved roads or grass, a model with large wheels is a great option. Under those same conditions, a stroller with small plastic wheels, such as those found on some car-seat carrier frames, some umbrella strollers, and some traditional strollers, might be difficult to push. If you want to run, use a jogging stroller only, with a fixed front wheel, or locked swivel wheel.
If you do have a car, make sure whatever stroller you choose fits inside easily. And give some thought to where you will put a folded, standing stroller in your house. Do you have the closet space for it? Or will it block a hallway if you have to store it there? A folded stroller in the hall, or standing inside a closet, might also be a tip-over hazard for a curious baby or toddler.
Some parents may start with a travel system and later add a lightweight umbrella stroller for easier quick trips when baby is a bit older. If a second child comes along, you can consider a tandem double stroller, in which, with some models, an older child can sit in the front, and the infant can ride in the back, snug in her car seat. If one parent will be on his or her own with the kids, consider getting something that's not too heavy, if possible, since you may also be carrying a diaper bag and a baby. A stroller you can open and close with one hand also helps, but many strollers don't have this feature. A deep storage basket can also make a big difference when you're out running errands. Owning a stroller that comes with a car seat (such as a travel system) or is compatible with an infant car seat you own can also simplify your life.
For two children, you can buy a tandem or a side-by-side stroller. Depending on the model and configuration, some of these can be used with children of different ages. You might see strollers with a little platform in the back so an older child can stand up and ride along while a younger sibling is in the stroller seat in front, but we don't recommend these, since the standing child could slip or fall. We have not tested these ride-along seats.