Pigeons are very easy to take care of, if you learn about them before you jump into it. They don't really require anything much different from other birds. They are fed seeds and grains, or pellets, like chickens. Like all other animals, they need fresh, clean water daily. Perches for roosting and nestboxes for laying if you want them to have babies. My first loft was made from a chicken coop. We just added a wire aviary on the front so they could get some sun. As long as they have an area to get away from cold drafts, they can withstand the cold (and they can also take a lot of heat if they have plenty of water).
Basically, they can be as easy or hard to take care of as you want them to be. They can also be as cheap or expensive as you want them to be. You can spend lots of money on fancy housing, fancy birds, and fancy feed and supplements, but pigeons can survive pretty simply. Sort of like how some people just let their chickens roam, while others pamper them to death
Each pigeon has his or her own personality and temperament. If you spend time with them, they will warm up to you and become very loving pets. Some of them are easier/quicker to tame than others. Some are just wild no matter what. But usually it depends on the bird and how they were treated prior, not so much the breed. Pigeons are naturally intelligent and curious.
As a rule of thumb, you'll want a min. of 1 square foot of space per bird. However, the more room, the better. You'll also want to make sure there are plenty of perches for the amount of birds you wish to get. And if you put in nestboxes, you'll need one or two for each pair (the bigger boxes can be one per pair, and you can put two nest bowls in there).
Pros: When you let them out, they'll come back if they are properly settled to your loft. Unlike most birds, which when released, won't come back.
There are over 300 breeds to choose from. I believe there is a breed out there for everyone
Homing pigeons are fun to take and release at a distance, and then try to beat them home. Most of the time, they will get there first. They can come back from 500+ miles.
Rollers are also fun because they do acrobatics in the air! They'll be flying along in their flock when all of a sudden...they'll drop in a flurry of backflips. They may do seven or more flips before correcting themselves and continuing flying as if nothing happened.
By raising pigeons, you are involved with very important and historical birds. If you think about it, it can make you feel pretty special.
There are many more, but I'll stop it at that for now
They can be used to hatch out chicken (depending on the size of the pigeon, they may be able to hatch one or two small eggs, or one large egg) and quail eggs! When I don't want my pigeons making more pigeon babies, I replace their eggs with these. Since chickens hatch out only a couple days later than a pigeon egg would, it works out well. And of course quail eggs hatch a little less than pigeons, so that works too.
Very good birds for kids. They will learn so much from them! I know I did (I got my first ones when I was 9).
Cons: There aren't many of these.
For one, hawks love pigeons. They love chickens and other birds too, but since pigeons are smaller, it opens up many more predators that can easily snack on them. Luckily a lot of pigeons are fast enough to get away, but hawks can be pretty sneaky! You'll want to keep an eye on them when they are outside their loft/enclosure.
Their young are not able to fend for themselves from birth. They require their parents to feed them until they are weaned at 25-30 days old. So that means if for whatever reason the parents aren't able to feed them, you'll have to step in and handfeed.
Pigeons only lay 2 small eggs at a time. This isn't really that big of a problem, but if you are expecting to get a lot of breakfasts from them, or if you expect to collect their eggs to sell to others, then you'll be disappointed.
Consider this a con if you'd like - pigeons are like potato chips! You can't have just one!