This is a normal Saiyan - basically the same as a Human except that all pure blooded Saiyan's have black hair (except brolly for some reason), and of course tail. They also have a liking for fighting from birth, they can turn Super Saiyan when they are strong enough (you turn Super Saiyan when you surpass your maximum strength in normal body and usually when you are under emotional stress or anger).
Saiyan's are born with tails so that they can turn into Oozaru form (giant monkeys). As an Oozaru a Saiyan's power is times by 10. Although if your tail is chopped of then you revert to normal and can't turn Oozaru form again. If your tail is pulled out you will revert normal and your tail will re grow in about a month.
The main advantages of being a Saiyan are being able to go Oozaru and SS (SS stands for Super Saiyan it is also written SSJ because translated directly from Japanese Super Saiyan is spelt Super Saiya-jin). Disadvantages are that you have to be really strong to turn Super Saiyan and if never done before ten Oozaru form can be hard to control.