Sand beds are the subject of intense debate within the hobby. In simplistic terms I will say that some folks are believers in deep sand beds that have a depth of greater than 4 inches (DSBs) which should never be disturbed, whilst some folks prefer a thin layer of sand that they siphon clean weekly, and still others prefer a bare bottom tank where they siphon off all detritus on a regular basis. A DSB stays clean by virtue of the small creatures that live inside it, while a thin layer of sand will need to be siphoned clean on a regular basis. If you have a sand bed less than 4 inches, you need to work on keeping it clean yourself and if your sand bed is more than 4 inches deep you need to leave it alone and focus on keeping your water pristine so the bed can "take care of itself", but all of this is a matter which is constantly debated and discussed amongst even the most advanced reefers so don't feel to bad if you don't have a perfectly pristine white sand bed.
Not sure how much that helps, but I hope you'll feel free to ask as many questions as you want since I am certain the good folks here on RC can help!
Joe