I need some information on updating kernel. currently I am using redhat7.0 version and I want to upgrade the kernel.

My questions are as follows

1) If I upgrade the kernel do I need to upgrade all other compnents?
(if I don't upgrade does it affects the working of server?)

2) accroding to redhat howtos
(www.redhat.com/.../s1-upgrade.html) they have specified few files which has to be upgraded. But in http://updates.redhat.com/ I have not seen the files they have mentioned, it contains some other files. in some other folder it contains lots of rpm files do need to install all the rpms? what has to be done?.

3)can you please send me a detailed documentation on upgrading the kernel.