Centos 6/RHEL set up matched Kernel files and install compile tools

Setting up the kernels on your Centos 6/RHEL installation is pretty straightforward and installing basic compile tools ensures that you can build from source if necessary, although it is recommended to use the repos unless this is unavoidable.

If you are using Nvidia graphics drivers this is essential and

Nvidia graphics users should follow the below sections on kernels and install original Nvidia drivers  or Kmod Nvidia Drivers.

There may have been a kernel update since the last release

meaning you have got 2 different ones installed 

$ rpm -qa | grep kernel  

Shows the kernel files you have, similar to below

kernel-firmware-2.6.32-279.1.1.el6.noarch
dracut-kernel-004-284.el6_3.noarch
kernel-2.6.32-279.1.1.el6.i686  New
kernel-2.6.32-279.el6.i686      Old

With old from the original install and the newly released one installed on update.

Reboot and boot from the new kernel (press the space bar)

Remove the old one

$ sudo yum -y remove kernel-2.6.32-279.el6.i686

And add matching headers and devel

$ sudo yum -y install kernel-headers kernel-devel

Repeat the command above to check they match as below

kernel-devel-2.6.32-279.1.1.el6.i686
kernel-headers-2.6.32-279.1.1.el6.i686
kernel-firmware-2.6.32-279.1.1.el6.noarch
dracut-kernel-004-284.el6_3.noarch
kernel-2.6.32-279.1.1.el6.i686

Now you have a correct /usr/src/kernels folder so you can install gcc and basic tools

$ sudo yum -y install gcc gcc-c++ automake autoconf make 

Add any others that you require and you should be able to compile without kernel errors.