Skin cancer can be detected early and it is important to check your own skin on a monthly basis. You should take note of new marks or moles on your skin and whether or not they have changed in size or appearance.
The American Cancer Society's "ABCD rule" can help distinguish a normal mole from melanoma:
The American Cancer Society recommends a skin examination by a doctor every three years for people between 20 and 40 years of age and every year for anyone over the age of 40.