Noob question:

[krg]

Hi guys,
Your replies have led me to ask another question..water changes..what exactly am I doing? I have some experience with freshwater tanks, and am used to vaccuuming the gravel when I do a water change. I was told with saltwater I don't want to siphon my substrate cause I have befeficial stuff there. So..am I just basically sucking up water and replacing it? Or am I just vaccuuming the parts of my Live Rock that I can vaccuum? I'm slightly confused on what to do to perform a 'proper' water change.
Thanks to anyone still reading and to anyone replying..I EXTREMELY appreciate it!!! Thanks to everyone who has replied. I look forward to learning some more!!! Take care,
Kennan