As for how much sand you will need, use this sandbed calculator to figure it out:
Also, you can do it either way, sand in then rocks, or rocks in then sand. However, it may be safer to put sand in first so if a rock falls or slips out of your hand, it will fall on to the sand and not the bottom of tank, possibly cracking or breaking it.
Using DRY aragonite sand is recommended, and not the use of crushed coral or crushed seashells. Those last two can lead to nitrate problems down the road because waste and detritus will build up in the areas where you or your clean up crew can not reach. You will also need to thoroughly rinse the dry aragonite otherwise your tank water will stay cloudy for an unnecessary amount of time. Instructions on how to clean the sand SHOULD be on the bag that it comes in, but in case it's not.. It's best to thoroughly rinse a few pounds of sand at a time until the water turns from a milky white, to a cloudy haze.
Also, it is best to buy the test kits now and test your water during cycling. There is no SET time for how long or how short a cycle will be, so if you didn't have a test kit and your tank cycled in a week and you waited three, you would have never known, and it sure would have been a big waste of time to wait that long. Which could also have posed a threat to kill the bacteria that established in there, since there would be no bioload(which comes from your fish and decaying matter) to keep the bacteria alive. So definitely get the test kit ASAP. However, during the cycling you will not have to test your pH levels because they will most likely be all over the place. The things you want to test for during cycling in Ammonia, Nitrite, and Nitrates, as Mitchell already said. After you provide an ammonia source and you see a spike of ammonia and then your levels begin to drop, you will know the cycling in coming to an end. Once your Ammonia and Nitrite levels read ZERO, your tank will be cycled. Then it is best to do a 30-50% water change to lower the Nitrates.
As for the amount of live rock, to create an ecosystem in your tank where the live rock will also count for a large portion of biological filtration, it is best to have at least 1.5-2lbs PER gallon of water.