Tarantuals are quiet, require little care, little space - In fact, they make an ideal pet, and many people have taken advantage of this and adopted a tarantula into their homes
Due to danger and stress to the spider, you won't be able to handle it too much, but there's little danger to the handler. They DO bite, and they are venomous, but the poison is likely to have as little effect on a human as a bee or wasp sting, though spiders are more likely to try to run than to fight. Even so, you'll still want to avoid getting bitten, and the best way to do this is to read and learn about spider behaviour before purchsing your pet.
Another danger from tarrantulas are the hairs on their abdomen which they will use to defend themselves when threatened. A vigorous rub on the abdomen from the spiders hindlegs will send a cloud of these hairs into the air. Any that land on skin will cause itching and irritation. These barbed hairs can easily get into the eye and penetrate the eyeball - If they do, you need to get medical help immediately.
Due to the dangers to both parties, Spiders should never be handled by children