water is heavy! your going to want to take everything out of the tank that you can. this all depends on the size of the tank, and the capabilites of the people doing the moving. also, things are going to die, prepare yourself for a cycle when you rebuild your tank. dont overload the container... you dont want to break a can or bucket and lose your livestock (etc.)
1. get a lot of buckets and heavy duty garbage cans.
2. move your fish to the QT
or buckets 1/2 full of water.
3. remove rocks and divide them up into the garbage cans. try to keep the cans on the empty side. you can cover the rocks with some water, or you can use wet newspaper and/or towels to keep some moisture on the rocks. dont fill the containers too high, because the water will slosh around.
4. use other buckets or cans to carry the sand. i would put some water in those containers to keep the sand wet. again, try not to make these too heavy to deal with.
5. remove the remaining water and put it somewhere, bucket, jugs, etc. once the tank is as empty as you can get it, then you can move it. i would recommend against moving the tank with anything in it, as you may end up spliting a seam with all the sand, water, rock, etc still in the tank as you move it around.
bottom line, is this is probably going to take all day. plan ahead, and make some space in the new place so that you can set up some stuff right away. start early and leave yourself a lot of extra time so you dont rush the process.
good luck, and have a search around the site, there are a few people that have documented their moves pretty well, and you can probably learn something from their experiences and mistakes.