I could look up your motherboard, but just by the name it sounds like it has a 533MHz FSB limitation, so no P4C 3.0GHz for you. You'll have to stick to the P4B 3.06GHz.
As for PCB, that's just short for Printed Circuit Board, or in other words, the hardware. Sometimes manufacturers realize that they made a mistake and so they tweak their manufacturing and release the 'fixed' hardware under the same product name but with a new version number. In your case you need your motherboard to be their version 1.02 (or higher) of the P4B533-E.
<pre><b><font color=red>"Build a man a fire and he's warm for the rest of the evening.
Set a man on fire and he's warm for the rest of his life." - Steve Taylor</font color=red></b></pre><p>