Ron, I favour putting airstones under sand/gravel etc. If you look in the vid - I posted above, the airstones/aircurtains are under the coralsand. I have also just set up another tank with blue lobsters/crayfish in, I used sand in that and have an airstone under the sand.
With my big tank, I have to be careful as if I have it on full blast, it turns into a snowglobe.
In sand however it will be ok depending on how much air is going into it.
First you need an airpump, these vary in size so get one suitable for your tank, you then need some airpipe, this goes from the pump to the airstone/curtain in your tank, then as aforementioned, an airstone/curtain, connect them all up and away ye go