hydro,
Depending on the amount of rock, get an adequately sized Rubbermaid trashcan. I used a 20 gallon for 45 pounds of rock and it worked out perfectly.
I had mine pre-mixed with salt when the rock arrived. I unpacked the rock and added it to the trashcan. You should have a powerhead for circulation and to help oxygen exchange and a heater to maintain a good temperature.
There is no specific amount of time. This would be like telling a new hobbyist their cycle will take exactly "x" number of days/weeks. The biggest time factor will be how much die-off there was during transportation. I got lucky and had little. I got the rock within 24 hours of it being packed.
This is where I've heard 2 methods. I followed method A:
A: Don't do anything to the water except keep the PH and heater running. Test the water in the trashcan for ammonia, nitrite, and nitrates. When you get 0 ammonia and 0 nitrite, you can safely add the rock to your tank.
B: Do method A, except do a 20% water change every few days.
Hope this help! Good luck!