I am not completely experienced myself, but I can give some hints that will help.
First off to overclock you wanna change the CPU FSB. Athlon made the processors so the multiplier can not really be increased I do believe. The ratio that you are talking about I believe is either the multiplier, or the ratio between the RAM speed and the CPU clock speed.
Also, when you overclok, eventually you may want to increase the voltages supplied to the CPU. Another thing to note is that the HT frequency may have to be lowered. I was not able to overclock mine until I lowered the HT frequency from x5 to x4.
One more tip. If you have dynamic overclocking you will want that disabled, and I believe you'll also want Cool'N'Quiet disabled if that is also on there. I'll let somebody else expand on this.
AMD Athlon 64 3000+ socket 939 @ 2.3 GHz
MSI K8N Neo2 Platinum motherboard
EVGA GeForce 6800 GT
2 GB DDR 400 (PC 3200) (2 x 1 GB sticks) (Dual Channel)
DVD player and seperate DVD RW drive
80 GB Western Digital Hard Drive
500 watt power supply
Sound Blaster Audigy
Logitech 5.1 surround sound speakers
SAMSUNG SyncMaster 710T LCD monitor
Aspire X Navigator Case