Five teenage martial artists (later six with the addition of Tommy) are granted morphers that transform them into a color-coded team based on paleolithic animals, of which they can summon giant mecha versions that combine into the Megazord. Jason, the leader and who I'm sure is supposed to be Native American considering the rest of the color coding, is the red ranger and the tyrannosaurus rex, which forms the body and head. His weapon is a sword. Billy is the blue ranger, the techie, and the triceratops, which is one of the legs. His weapon is a staff with a trident at each end that can break in half to make two weapons. Trini, the yellow ranger, is the Asian chick who is smart enough to know what Billy's babbling about most of the time but down to earth enough to translate it for the rest and is the saber-tooth tiger, which is the other leg. She uses two daggers. Zack is both black and the black ranger, dances a lot, and is the mastodon, which forms both arms. His weapon is an axe. Finally, last is Kimberly, the pink ranger, a gymnast, and the pterodactyl, which forms the chestplate of the Megazord. She uses a bow. All the weapons can be combined to form a cannon of sorts, and is sometimes used to defeat villains although mainly it's the Megazord that deals the final blow. The last addition to the team is Tommy O'(something or other, I can't remember of the top of my head but I think it's Malley) the green ranger who was initially given his morpher by series villain Rita Repulsa, and who uses the dragon dagger. Also unique to him is a golden chestplate that makes him have much greater defense than the other rangers, and he summons the dragonzord. When combined with the Megazord, it forms a sort of cape.
Rita Repulsa is the initial villain and was locked on the moon 1,000 years ago by Zordon, the being that gave the rangers their morphers. He only appears as a floating holographic blue face in a tube, while Rita is a woman with a hilariously bad dub job that sounds like Roseanne. Her primary soldier is the Putty, which is just a series of guys in a gray suit with black tiger stripes and a laughable face that get their head kicked in every time they appear whether or not the rangers are morphed. Later Lord Zedd replaced Rita and the putties got chestplates that made them a little tougher, but also gave them a glaring weakspot as there was a giant Z on the chest. So much as sneezing on the Z would kill the putty. Anyway, Rita's other minions were goldar, some weird flying ape thing in gold armor, and two who's names I can't remember. One was basically a blueberry and the other was a goat if a goat looked like a scientist and sculpted things. These sculptures were turned into monsters by Rita and sent to Earth, where they would get their asses kicked by the rangers and 99% of the time get turned into giants, whereupon they would get their asses kicked by the Megazord. The other 1% they were weak enough that the rangers just finished them off on foot.
As for supporting details, whenever there wasn't fighting going on the show mainly took place in the Youth Center of Angel Grove, which was run by a fat guy named Ernie. There was a bumbling comedy duo of dimwitted villains named Bulk and Skull and I think they're still on the show even though it's been like two decades. They basically tried to A: take credit for all the ranger's kills and B: find out who the rangers were. Somehow no one ever discovered it despite the fact the rangers always hung out together and always wore their respective color. All in all it was a fun show if incredibly cheesy and, along with MST3K, gave me a love for things So Bad It's Good.