The right hand one the thumb shifter shifts you DOWN (to larger ring = lower gear). Index trigger shifts you up (smaller ring = higher gear). The left hand one shifts your front derailleur and is set up opposite. Thumb shifter shifts up to big ring, index finger shifter shifts down to small ring.
Oh, and just pedal lightly when you're shifting. One or two quick revolutions should do it. Don't shift under full bore. Your drivetrain will thank you. My SO is yelling "And don't forget to shift DOWN before you stop!!!"