Welcome to the forums, mrcraven!
I'm sure you've heard the phrase "open source software"... well what that actually means is you never need to GUESS "what is this update... why am I being prompted to install a new kernel?"
packages.ubuntu.com is the website that explains every version, change, and update to Ubuntu software. If you want you can even view the source code! Every package has a "changelog" for example:
http://changelogs.ubuntu.com/changel...2.38/changelog
So for example you can see that the April 20 update added some wireless compatibility, the March 14 update bumped ABI, etc.
In practice I recommend simply saying "yes" to all of the kernel updates. They are minor bug fixes and security patches that may or may not affect you. You're running 2.6.32 which is a very stable and well-tested kernel.