Overclocking the radeon hd xfx 7850

Hello, this is my first time overclocking the gpu. I hope that anyone can please help me with overclocking the gpu

the stock core is at 860 MHz
and the stock memory is at 1200 MHz

what is a stable overclock? i dont need it to be highest, i just want to overclock it to a safe limit.

also what fan speed % should i take it on? stock is 40%

and how much power control settings should i put it on, it is the maximum power limit? stock is 0%

and what should the temp be at on a stable overclock

i use the amd engine control center to overclock it

ty for ur responds in advance

ollinho