Patience is key... take your time. Adding too much too quickly will wipe everything out in your newly established tank.
As Mark says, check your ammonia levels, and if it is at 0, you know that your tank has cycled.
By adding your established rock and sand, will only help speed things up, but check your numbers.
If you really want to, you can add a clown, but it just adds to your bio-load, and if things aren't cycled, can just make the cycle longer.
Good luck.