How can I monitor the active processes on the server?

Telnet/SSH to your machine and type
top
it will show a list of active processes in real time. You can sort them by CPU usage, memory usage and runtime.
form more informations type
man top

One of the modules in webmin (http://www.webmin.com) gives you a nice readout of all the processes. 'top' seems to only give the ones that using most CPU/Memory etc, though maybe with a few other variables it could give you more information.

Try the following command in your ssh terminal:

ps -ax


You'll get a list with all needed information.. :-)

PID TTY STAT TIME COMMAND
123 ? S 0:30 [....]