Normally, only the alpha pair of the pack breeds, which is a kind of organization not uncommon to other pack-hunting canids including the Dhole and the African Hunting Dog. Mating occurs between January and April, happening later in the year as latitude increases.
A pack usually produces a single litter, though sometimes multiple litters will be born if the alpha male mates with one or more subordinate females. Under normal circumstances, the alpha female will try to prevent this by aggressively dominating other females and physically separating them from the alpha male during the mating season.

A wolf resting at the entrance to its den. Also note how its coloration blends in with the environment.

The gestation period lasts 60–63 days, and at the weight of 0.5 kg (1 lb), the pups are born blind, deaf, and completely dependent on their mother.
There are 1–14 pups per litter, with the average litter size being about 4–6.
Pups reside in the den, where they are born deaf with their eyes closed, and stay there until they reach about 3 weeks of age.
The den is usually on high ground near an open water source, and has an open "room" at the end of an underground or hillside tunnel that can be up to a few meters long.
During this time, the pups will become more independent, and will eventually begin to explore the area immediately outside the den before gradually roaming up to a mile away from it at around 5 weeks of age.
They begin eating regurgitated foods after 2 weeks— by which time their milk teeth have emerged— and are fully weaned by 8–10 weeks. During the first weeks of development, the mother usually stays with her litter alone, but eventually most members of the pack will contribute to the rearing of the pups in some way.

After 2 months, the restless pups will be moved to a rendezvous site, which gives them a safe place to reside while most of the adults go out to hunt. An adult or two will stay behind to ensure the safety of the pups. After a few more weeks, the pups are permitted to join the adults if they are able (they tag along as observers until about 8 months, by which time they are large enough to actively participate), and will receive first priority on anything killed, their low ranks notwithstanding. Letting the pups fight for eating privileges results in a secondary ranking being formed among them, and allows them to practice the dominance/submission rituals that will be essential to their future survival in pack life.

Wolves typically reach sexual maturity after 2 or 3 years, at which point many of them will feel compelled to leave their birth packs and search out mates and territories of their own. Wolves that reach maturity generally live 6–8 years in the wild, although in captivity they can live to be twice that age.
High mortality rates result in a relatively low overall life expectancy for wolves. Pups die when food is scarce; they can also fall prey to other predators such as bears, or, less often, coyotes, foxes, or other wolves. The most significant mortality factors for grown wolves are hunting and poaching by humans, car accidents, and wounds suffered while hunting prey. Wolves are susceptible to the same infections that affect domestic dogs, such as mange, heartworm, rabiescanine distemper, and such diseases can become epidemic, drastically reducing the wolf population in an area.

All data on this page was taken from http://en.wikipedia.org/wiki/Wolf