Welcome to the forums man. This place has all the info you need and lots of smart and tech savy guys.
DSM = Diamond Star Motors, it was a joint venture between mitsubishi, Eagle, And Laser back in the early to mid 90's. Just keeping it short, if you search the forums you can find out more of it's history.
Also as i and everyone else on this forum would recommend, do ALL of your maintenance FIRST before starting any mods whatsoever on your car, your car will thank you for it and will definately lessen the chance of something blowing up or going wrong.
Afterwards go through the upgrade paths and just guide yourself along that.
Tech Guide: 2G 4G63t Upgrades: Stage 1 Power - DSMtuners
Tech Guide: 2G 4G63t Upgrades: Stage 2 Power - DSMtuners
Good luck and have fun man.