cron is a JOB scheduling tool. (see cron and crontab man pages).
CPU scheduling makes me think you want to change the way the CPU time slices. This is a much more complicated task and likely has to be done in the kernel.
Linux has complete source code available so you can change this (assuming you know C programming). You might want to have a look at
http://www.linuxfromscratch.org/ which allows you to build customize your own distribution of Linux from the ground up.
RedHat is now the commercial version of Linux supported by the company of that name. The open source version from RedHat is now called Fedora (Core 4 being the latest). You can download that without having to build it from scratch then also get the source for its kernel so that you can work on the time slicing.