Can I overclock my system?

Power supply: Thermaltake XP550 NP 430 W
CPU: AMD Athlon X2 6000+ 3ghz
CPU Fan: Thermaltake Big Typhoon CL-P0114
Mobo: Gigabyte GA-M52S-S3P revision 2
Ram: Kingston 2gb (1gb x2) PC2-5300 DDR2 (333 Mhz)
Graphics: 512mb 9600 gt gigabyte
Cooling: 120mm fan at the back upper side (I think it's intake)
Temps: Idle: 35
Load: 55

Is my system ok to overclock? My friend said I could get it up to 3.6ghz but I really doubt thats gonna happen.

And BTW this is something else but should I put a fan at the front bottom so that there's a constant airflow? My computer doesn't seem to be overheating so I don't think it's necessary.


Google