for a look at some boards used for overclocking..and the results..look here
http://www.cpudatabase.com/CPUdb/
they have cool databases of peoples overclocking results..usually they show the cpu, the motherboard and then remarks about cooling, voltages etc etc.
As far as telling which processor you have, you can probably download and use SiSoft Sandra..the benchmarking tool...it has readouts about system info. There are probably easier ways to tell but its late and I cant think of them.
The ppga 533 celly was the fastest of the ppga type. Then they went to fcpga...fcpga is often called "flip chip". The fcpga started at 533.
So you have two different scenarios. If you have the ppga celeron then you dont have as much "headroom" to work with since it was near the end of the product line and it was already stretched pretty far. But if you have the fcpga..it was right at the beginning of the product line so it had a lot of room for expansion etc...in other words the architecture of the cpu would eventually reach high speeds but they always start of on the low end and build up..probably for marketing reasons, lol. But anyway the analogy could be like a small block chevy engine..if it is a 283 then it has plenty of room to be stroked and bored...but if its a 383 it has already done most of what it can do.
JP
PS..if you can see any of the edge of the cpu itself..the ppga's were black and the fcpga's were usually green I think.