kernel questions

[Douglas Alves]

At start-up, the GRUB on my desktop lists 4 kernels:
  2.6.8.1-4-386
  2.6.8.1-4-386 (Recovery mode)
  2.6.8.1-3-386
  2.6.8.1-3-386 (Recovery mode)

Are the last 2 unnecessary for a newbie like me?
Can I uninstall them? or should I remove them from menu.lst?

My desktop PC has a Celeron 2.5 GHz:
Synaptic says I have installed:
  linux-image-2.6-386        version 2.6.8.1-14
  linux-image-2.6.8.1-3-386  version 2.6.8.1-16.1
  linux-image-386            version 2.6.8.1-14

Is any one redundant and can I remove it?

Since I have a Celeron, should I install 
  linux-image-2.6-686 and/or
  linux-image-2.6.8.1-3-686 ?

What does the SMP mean in this Base System list, and what is that
kernel's purpose?