Live sand, dead sand, you can start with either one you like. Just make sure that it is calcium carbonate based sand, thats what you want.
My preference is having an ootlic style sand like Southdown, Yardright or Old Castle playsand. This means that the sand is more eggshaped/rounded not many sharp edges. This means that it will hold more bacteria and be a better substrate for your infauna and micro infauna (all those little critters and bugs). It also means that you would have different grain sizes, the smaller particals usually working there way to the bottom of a DSB or deeper sand bed where the nitrates can be converted.
If using live sand fine you can just place it and then put your rocks on top of it, eventually it should be seeded with pods and worms. If dry I recommend pre curing it to get the bacteria on it, this can be done with old tank water from a water change on your main tank. That also means that you can do it cheaper than purchasing live sand.
Lots and lots of threads about this type of thing if you care to do a search.
Thomas