how to start/stop/restart processes

Question

As a new comer from Windows OS, I wonder how to start/stop/restart a service on Mac OS X Snow Leopard 10.6.8 ?(it's straight forward on Windows using its Task Manager). I tried Activity Monitor, but it only kills processes, it does not start them. I tried the command: launchctl stop *servicename* and then the command launchctl start *servicename* after I hit return on keyboard after each command the terminal does not show any message so it must be successfull, but when I check out the result in Activity Monitor, it sounds that this command is useless because it has no effect on that process in Activity Monitor.

p.s. I'm sure I typed the right name of the process, I grabbed the name from the list using the command : launchctl list

EDIT: (ps auxwww command output lines)

line1:

zend 204 0.0 0.1 602396 2684 ?? Ss 10:53AM 0:00.72 /usr/local/zend/gui/lighttpd/sbin/lighttpd -m /usr/local/zend/gui/lighttpd/lib -f /usr/local/zend/gui/lighttpd/etc/lighttpd.conf -D

line2:

root 202 0.0 0.0 623124 756 ?? Ss 10:53AM 0:00.00 /usr/local/zend/bin/watchdog -c /usr/local/zend/etc/watchdog-lighttpd.ini -u zend -g zend -s lighttpd