Check this out for OC instructions:http://www.anandtech.com/showdoc.html?i=1345
Don't get me wrong here...I dig Tom's but Anand had the clearest instructions I found. That will help a lot but playing with your BIOS or jumpers is the best way to figure it out. Trial and error is the best teacher...Just make sure you know how to reset the board and that you've got an okay HSF.
Oh, and I'd say go for the Duron. If your goal is 1ghz then get the 750 version. Then you can just set the Bus at 133 and you're there. If it runs stable at the frequency you can mess around with the Multiplier to get the clock higher. I got an 850 TB and quickly learned that I should've gotten a 750 and save some money. It won't run much above 1050mhz and 1000mhz was my goal anyway.