Errata updates for RHEL

[Venkata Vuppala]

Hi Experts,

I am new bie to Linux from Solaris. We have two servers which came to us as part of  transition. I registered the machine using rhn_register ( one is 4.1nehant and the other 5.2 )
and when I clicked on the portal there are 100's for 5.2 and around 5000 for 4.1 ( Errata updates) available to be installed.

Is it a good advice to configure yum & up2date in this circumstances or I can keep selecting and click for install. Please advice.

Thanks,
Venkata Vuppala