Would help to know what Linux distro you are using.. there are a few differences in the commands for some functions between distros.
In Debian you can use :
to view/alter what services run at startup sysv-rc-conf
To view current running processes ps
To stop or start a service manually /etc/init.d/servicesname stop
is a good command to learn as well.. with apropos you can search for a command to do a specific task...
for instance if you wanted to search for some commands that relate to processes..
it-etch:/var/log# apropos processes
exiwhat (8) - Finding out what Exim processes are doing
fuser (1) - identify processes using files or sockets
gnome-system-monitor (1) - view and control processes
killall (1) - kill processes by name
killall5 (8) - send a signal to all processes.
mysql_zap (1) - kill processes that match a pattern
peekfd (1) - peek at file descriptors of running processes
pgrep (1) - look up or signal processes based on name and other attributes
pkill (1) - look up or signal processes based on name and other attributes
ps (1) - report a snapshot of the current processes.
pstree (1) - display a tree of processes
pstree.x11 (1) - display a tree of processes
renice (1) - alter priority of running processes
smbcontrol (1) - send messages to smbd, nmbd or winbindd processes
You certainly won't always find the command you are looking for on the first try, but it is a good tool for learning what some of the commands are in Linux. Once you get your list of commands you can use man to learn more about the specific command i.e.: man ps