Well, if the fish you got came from a healthy looking tank, chances are you've got no problem. i have a black moor named Shai who will sometimes rest on the gravel. Do you have fancy goldfish? Chances are, since fancy goldfish have strange body shapes that weigh them down and make it harder for them to swim, they rest more. Also, have your goldfish done this since day 1? If this is a new habit, there might be cause for worry.

Yes. Check your ammonia and nitrate levels, you might be surprised. "Head-standing" can be a sign of water quality or swim bladder problems. In either case a water change & feeding boiled, skinned peas for three days should help. Check the bottom sleeping fish for gravel stuck in his mouth as well.

they have the symptoms of Nitrite Poisoning you need to buy a water test kit. I use the Jungle brand 6 test Quick Dip strips, which test for Nitrate, Nitrite, Hardness, Chlorine, and PH. I also use the Ammonia Quick Dip strips. All pet stores sell these, just ask for them at the place where you bought the fish and they'll help you find them. The reason for the tests is to make sure that your fish don't die from Nitrite Poisoning aka New Tank Syndrome. Read these two articles to find out what Nitrite Poisoning is and how to prevent it. http://freshaquarium.about.com/cs/disease/p/nitritepoison.htm http://freshaquarium.about.com/cs/biologicalcycle/a/nitrogencycle.htm There is no water treatment or cure for it, all you can do is test the water, and than remove 50% (if test results in stress levels) to 90% (if tests result in danger levels) of the water in the tank, and keep testing and changing water every single day, until the nitrite cycle stabilizes (which can take any where from 3 days to 2 months.) This can be the roughest week or month of your fishes lives, but once the nitrite cycle settles again, you'll only need to do tests and water changes one per week (50% change once each week, and 90% change once per month), or any time the test comes back toxic.