Hi Aaron,
Water changes depend mainly on your fish load and the quality of your filtration... ie:... lotsa fish.. low filtration... more water changes.
Some do changes every day (discus keepers).. while others do changes every three weeks or so... even longer.. months sometimes
The "NEED" for a water change is when the balance of your water starts to deviate, especially the ammonia side or nitrites.. which you don't want any of, but low levels of Nitrates are not too bad.
So... if you see any sign of ammonia buildup... then it time for a water change.
Good filtration and live plants will help keep your tank stable, but overloading with fish stocks or overfeeding will soon upset this, no matter how good your filters are, or how many water changes you do.
Filters should only be "rinsed" in a container of tank water so as to preserve the bacteria. Change only half of the media at a time (if this is possible) or setup a standby filter (a corner box type or HOB) to tide you over if you "have" to change the media for new stuff.
HTH