You didn't say wich MBO You're using.
The chances are that the CPU and MBO don't work with Your current jumper settings.
Anyhow, check if there IS a beeper at all and if there is one (my MBO don't have one) maybe you didn't plug it in.
If You have beeper that is pluged in, You should proceede with theese steps:
1. Unplugg everithing but CPU, it's fan and a beeper.
2. Turn it on.
If You hear no beeps - try unplugging CPU. If You hear beeps without CPU then could be a jumper settings on MBO. Or a fried CPU.
If You hear beeps with CPU then plug in memory stick.
You should hear different beeps now.
If you hear same beeps as without memory installed then the problem is with memory stick.
If the beeps are different then POST detects that there is no VGA installed. That means that the memory passed a POST.
Now try plugging a VGA in.
If the beeps end there then it could mean that the MBO is faulty or the AGP slot is dusty.
Anyway, you should try a different MBO or a different CPU.