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Get a bunch of either 5g buckets or rubbermaid containers, fill them with the tank water and put all the live rock and fish in them. Also, make sure you buy the sand you'll need and have a refractometer or hydrometer.
When you get back to your house, make sure you get heaters into the containers so the water doesn't get too cold and possibly powerheads in each one to keep the water moving.
Then start setting your tank up. The way I would do it is:
Set up the stand and tank where you want them (make sure the tank is level!)
Fill the tank up half way with fresh RO water and salt mix (to a salinity of 1.024-1.026 and the appropriate temp.)
Make sure you have powerheads running in the tank to get the salt mixed up
Once the salinity is at the proper level, start setting up your live rocks how you want them in the tank (try to make sure the rocks are submerged under water so you don't kill anything living in the rocks). Once you have the rocks set-up and they're stable, now it's time to add your sand, pour the sand around the base of your rocks making sure your sandbed is even everywhere.
At this point there will be a huge sand storm going on in your tank, wait for it to settle. When it starts to clear up, I would take your powerhead and use it to blow off all the sand that has settled on your rockwork. Now, use the rest of the water that was in the container you used to transport the rocks, and top off your tank with that. When it starts clearing up, it should be ok to add the fish in.
