Birds can be incredibly rewarding pets, and while they don't require quite as much time and energy as a dog, they certainly need their share of care and attention. They come in all shapes and sizes, and if you're new to bird keeping you should read up carefully on the type of bird you're getting - you don't want to end up with something that needs more care than you're able to give it.
While it's not true for all species, a general rule is that the larger a bird is, the bigger the commitment needed: bigger birds tend to be louder, more demanding and will of course need a larger and more expensive enclosure. Don't forget that some species of bird love to socialise, and it's often not much more trouble to have two or more than it is to keep one.
Birds make particularly good pets for people who live in apartments or other places where space is limited: as long as there is room for an appropriately-sized cage, birds will thrive in a variety of environments. They're also ideal companions for people for people who can't go outdoors much, and for families with children (as long as they understand the need for careful handling).
Novice bird keepers should set their sights on the smaller, more commonly-owned species: a canary is a good choice, as they don't need handling, are relatively quiet and are happy in a cage by themselves. More experienced owners might consider the many different species of parrot, who have more demanding requirements but make wonderful and affectionate pets.
It's also worth remembering that many species of bird live a long time - male canaries usually live around eight to ten years, and some macaws can live for around 75 years! Be sure you're prepared to care for a bird for its entire lifespan, and that you can make arrangements for their care during holidays and so on.