It's been a long time since I've overclocked an old K8 based processor, I'm actually spoiled myself with unlocked multipliers.
You need to look in your BIOS for base clock/ reference clock, I can't recall the exact name. The default value is 200, that number x your cpu multiplier is how you get your clock speed. Example would be Base clock 200 x cpu multiplier of 13 = 2600Mhz aka 2.6Ghz.
You need to increase that 200 by small increments, I would go 10 at a time, so 210, 220, 230 etc. Than use Prime95(google it to find a download), cpuz, and hardware monitor. Prime95 is designed for stress testing to check for stability, you'll want to run it for several hours. CPUZ will show your clock speed and other system information, hardwaremonitor can monitor your temps.
If you find your system to be unstable, than you need to locate cpu vcore and increase your voltage. I don't know the default of your processor, but it's probably in the 1.3-1.4V range. Increase voltage in small increments, too much voltage will kill your system. I wouldn't move it more than .05V at a time.
Since that base clock of 200 also effects your ram speed, and hypertransport speeds, you may need to drop their respective multipliers by 1 to maintain stability.
Hope that helps, sorry I can't be more precise, I'm working off memory of an overclock I did 4 years ago.