You don't have to have anything PRINTED and ready to go. Requests can vary widely. However, do have a complete, edited synopsis ready -- a proposal, if appropriate -- and at least the first 50 pages (minimum of the first chapter). I always complete my manuscript before I, or my agent, starts to submit, but I know that many--I think most--here don't believe that's necessary. I respect and understand where they are coming from and I have no objective reason to, and won't, disagree with them, but I won't change what's been successful for me.