super saiyan= once you get a certain amount of PL you press the 'z' button and your character with transform. some examples are trunk he starts out with 700,000 PL once he aquires 1,000,000 PL you can press Z and he will transform to a super saiyan. They aren't all the same. Goku for example starts off with 750,000 and transforms at 1,750,000. vegeta starts off with 700,000 and transforms at 2,000,000 majin buu starts off at 1,250,000 and transforms at 3,000,000 cell starts off at 900,000 and transes at 1,900,000 etc. If you put your mouse over the character name it tells you all about them.
for melee read the manaul. there is too much to explain. check either Torlorn's post or my sig.