Well, if that is an 866, then you are already running with 133mhz bus speed, so you will need some really good ram to get you flying...if you set your front side bus to 140mhz(in bios), that will get you 910 roughly...and is usualy attainable for standard pc133 mem....but right now fast pc150 cas2 ram is cheap.
If any of this dosen't make sence to you, feel free to brows the overclockers.com main page for beginers guides, usefull tips, etc.
I'm sure somebody has the same board as you, and can give you specifics that I can't, but you have a good board there, and should give you a stable overclock, provided your other components can handle the bus speed.
Good luck, and if you can't figure it out, come back.somebody's always here