Well it really depends on how good your chip is. There have been cases I've seen of the 750e reaching well in excess of 1Ghz, although you would need to replace the stock fan if you're considering going for that. Overall, it doesn't seem to be as good an overclocker as the 700e, or 600e and the coppermines before that. All I can say really is try and bump the FSB up notch by notch and see how fast you can go whilst maintaining a good level of stability. Be sure to keep a close eye on your PCI and AGP speeds when setting the FSB. As you probably know, 33Mhz is the standard PCI bus speed, and you don't really want to go too far in excess of that...
Good luck.