just received the bag of sand that i need to put into the tank... i already have live rock in the tank and its been aquascaped... should i just dump the sand into the tank straight from the bag? is that ok?

Any livestock in the tank in addition to the live rock? If not, add your sand slowly until you reach the level that you want. Keep in mind you'll have a big dust storm in the tank until it settles (usually 24 hours). If you have livestock in the tank and depending on how much sand you wanted, you would have to add incrementally over a longer period of time.

ohhh ok, thanks... no livestock in the tank yet.. so just dump the sand in slowly until i get the desired amount in... its ok for me to leave all the pumps and skimmers on while i add the sand?

No turn off your pumps and skimmer. Leave the skimmer off until the sand settles you can turn your pumps back on after the sand is in.

Just do it sowly then when it settles get in there with a clean brush and clean any sand of your live rock

Run down to Lowes, get yourself a 2 foot PVC pipe with a 2-3" diameter. Put the PVC in your tank and sssssllllloooowwwwwllllllyyyyyy pour the sand it. Gets the sand where you want it with a bare minimum of cloudiness and you don't have to run behind it with a turkey baster to clear off your rock.