Okay, first you have to get the REMOTE CONTROL from AUNT in WELLING VILLAGE.
1) If you are less than level 10 you can go to KAMA CAVE in KELAN VILLAGE and auto there for about 3-6 hours, and when you sell the ORES to the SHOP KEEPER you will gain a few thousand GOLD.
2) If you are level 10 to 15 you can auto in CHICKEN PEN in NORTH ISLAND for about 4-8 hours, selling that you will get a few thousand GOLD
3) If you are a Level 15 or higher you should go to the TIP of SOUTH ISLAND and auto there for 4-8 hours and you will get a few thousand GOLD
This really works, after a hew days of doing this I have already gainded 9000k! Good Luck!! :)