I'm having issues with Apache processes going upwards of 50% CPU usage, I know that I should isolate the problem, but in the short term, does anyone know a way that I can automatically kill any HTTPD process that has exceeded a set CPU usage limit? Running Apache 1.3.4 (not comfortable with upgrading to 2 yet, my last attempt failed as I am still learning the ropes of Linux server administration.

First, upgrade Apache to the latest legacy version, which is 1.3.35 -- you are waay behind. See if that helps.

Like fyrestrtr said, upgrading to the latest Apache 1.x version could be a good idea. Also upgrading your PHP version, if you indeed use PHP, would help. In addition, limiting the resources PHP can use through php.ini (mainly these three variables: max_execution_time, max_input_time, memory_limit) could help.

However, it is still possible that you will continue experiencing these issues I use a program called PRM to solve this problem: http://rfxnetworks.com/prm.php - it is run through crontab and will kill all processes that use more memory/cpu than you have allowed them to.