Calico isn't a breed. It's a tricolor coat of white with patches of black and orange, or soft gray and cream in the dilute version. The pattern shows up in domestic shorthairs and longhairs as well as many pedigreed breeds. Because the color gene sits on the X chromosome, nearly every calico is female, and the rare males are usually sterile.
Most calicos you'll meet are domestic shorthairs, so size and care look like those of any house cat: about 6 to 12 pounds, a lifespan of 12 to 18 years, and moderate shedding. Weekly brushing is plenty for short coats, and longhaired mixes need more. The "tortitude" reputation hasn't been confirmed by research, so age, upbringing and how a cat acts around people tell you far more than her patches.