cleaning tank

The fish stay right in the tank, the best way to do this is to get a gravel vacuum and use it once a week to vac. and remove 20-50% of the water and replace it with fresh dechlorinated water. Make sure to rinse your filter media in tank water also, that way you don't kill off all your bacteria from the chlorine in most tap water.

Unless absolutely necessary b/c of some disaster, removing the fish for cleaning the tank is very uneccessary and very stressful for them

I second that, you never want to completely empty your tank and clean it, it will kill off your bacteria and cause you to have to re-cycle. The gravel vac workes great, and your fish just hang out in the remaining water.