A C560 IN MOUNTAINOUS TERRAIN STEPPED DOWN TO AN APCH FIX EARLY ACTIVATING GPWS TERRAIN WARNING. THE PILOT CONFUSED THE MFD WAY PT WITH THE CHART FIX.

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WHILE EXECUTING GPS RWY 8 APCH TO ZZZ; I MISREAD THE CHART AND BEGAN FIRST STEP-DOWN AT ABC SHOULD HAVE WAITED UNTIL ZZZ. WHILE DSNDING; GPWS ISSUED 'CAUTION -- TERRAIN' AURAL WARNING. IMMEDIATELY LEVELED OFF; CHKED CHART AND DISCOVERED ERROR; CLBED TO CORRECT ALT. REST OF APCH AND LNDG WERE NORMAL. I'M NOT SURE WHAT FACTORS LED TO SELECTING THE WRONG STEP-DOWN. BUT ONE WAS THAT THE WAYPOINT ZZZ WAS DISPLAYED AS SUCH ON THE MFD DISPLAY BY THE FMS; BUT ON THE INST CHART THE WAYPOINT IS LABELED BY '7.0 NM' IN LARGE BOLD TYPE WITH ZZZ IN LIGHT ITALICIZED TYPE SURROUNDED BY BRACKETS AND VERY DIFFICULT TO READ. I REMEMBER ON PASSING ABC A MOMENT OF CONFUSION TRYING TO RECONCILE THE TWO; AND HAVING BEEN FOCUSED ON THAT WAYPOINT AND NOTICING IT AS A STEP-DOWN POINT; I MUST HAVE SUBCONSCIOUSLY THOUGHT I WAS PASSING THE WAYPOINT PREMATURELY. LESSONS LEARNED -- WHEN FLYING APCHED WITH MULTIPLE STEP-DOWNS; IT IS ESSENTIAL TO VERIFY AND RE-VERIFY EACH STEP-DOWN; WHERE IT BEGINS; HOW YOU WILL IDENT IT; AND WHAT THE ASSOCIATED MINIMUM ALT IS. ALSO; TAWS IS A HUGH SAFETY FACTOR WHEN EXECUTING INST APCHS.