Saiyajins:

Saiyajins are a powerful race of humanoids. The gravity of their planet (Vegita) is 10 times that of Earths, meaning the average Saiyajin has a STR of at least 28 (or more). They are also very tough physically, and can survive a great deal of punishment. Saiyans (in general) have black hair and brown monkey-like tails.

During a full moon, a Saiyan can transform into a huge 60' tall were-monkey, a form capable of demolishing a city with ease. Several of these were-monkeys can easily wipe out the population of a continent or even a whole world. Cutting off this tail will cause the Saiyajin to return to his (or her) normal form. Tearing this tail out (by the roots) will eliminate the chance of a Saiyajin becoming a were-monkey as well as allowing the Saiyajin to assume Super-Saiyajin form.

The racial powers of a Saiyajin are as follows:

Aa Saiyajin can live in excess of 1000 years. I don't know about that, but they seem to be a very long lived race. Vegita also makes the comment that after a Saiyajin matures, his hair stops growing, remaining in same way for the rest of the Saiyajin's life. Other powers are possible.

Saiyajins also get the following disadvantages standard:

Accidental Change: To Were-Monkey Form Under a Full Moon (Uncommon, Always
Distinctive Features: Tail (Concealable
Physical Limitation: Physical Weakness if Tail is Grabbed

The tail is a Saiyajin's one real weakness. If grabbed, the Saiyajin will collapse, unable to stand. Once let go, the Saiyajin will almost instantly regain their lost prowess. Note: certain Saiyajins have trained themselves to ignore this effect and don't have this Disadvantage!

Super-Saiyajin:

If a Saiyajin has their tail removed, then that Saiyajin can assume a high-energy state called "Super-Saiyajin." The requirements for becoming Super-Saiyajin (a.k.a. SSJ) is the Saiyajin in question must get angry -- very angry.

As with many things in Dragonball, the Super-Saiyajin form has several stages, each more powerful than the last.

Super-Saiyajin Stage 1:
This form of Super-Saiyajin is marked by the Saiyajin in question assuming an aura of energy about the body. The hair goes yellow-gold, the eyes go bright blue and the body bulks out a bit. This form is written up like this:

Super-Saiyajin Stage 1: STR+5, DEX+5 , and chi powers double, hair turns yellow, yellowish flame surrounds the Saiyajin.

Super-Saiyajin Stage 2:
A Saiyajin must have reached their maximum SSJ 1 energy level before assuming SSJ2. Upon reaching SSJ 2, the Saiyajin's hair gets even longer and more spiky, the aura is accompanied by electrical discharges, and the body gains an immense amount of muscle mass.

Super-Saiyajin Stage 2: Aid STR+7, DEX+4, chi powers double again.

Super-Saiyajin Stage 3:
It is accompanied by massive electrical discharges and bolts of lightning playing across the body. The face becomes very lean and feral, while the hair falls down past the waist in a thick mass of golden-yellow strands. This form is very, very powerful (but only useable for a very short time). I have not attempted to write it up, as it goes beyond the scale of what I am attempting to cover in this supplement. Suffice to say that is should be defined as: STR+10, Dex+9, chi powers double. This Stage can be assumed straight from Stage 1, but the user needs to be especially driven.

Super-Saiyajin Stage 4:
I am going to not bother about trying to define it. Suffice to say that at Stage 4, Saiyajin is capable of shattering planets with ease and can probably wipe out a whole solar system single-handedly.(not a used stage)