Depends on how predictable the project is. It's a waste of time to enter too many steps if there's a good chance that you're going to have a change of plan before they are done. The level of detail you use for breaking down the project also depends on how likely you are to be interrupted at any given point; ideally, you want to capture exactly as much state as you need to resume after your interruption without forgetting to do something, or repeating something unnecessarily, even if the interruption is a lengthy one. You're trying to free your mind of the need to remember all of these details, after all. If Joe is someone who works in your office and is readily available to sign contracts, you might not need to break that down beyond "Get contract signed by Joe". If Joe is a flake and needs to be hounded regularly to get something signed, it's probably good to have some more detail in there to keep the pressure on Joe (and maybe to document your efforts at getting the contract signed!)
I try to keep a couple of future steps sketched out so that I can always know what to do on a project right away. It's too easy to let something bog down otherwise. I'll put together a longer collection if it is apparent that more thought will be required to determine the right course of action. When I do reviews, I try to make sure that all projects have a next action, and preferably they have enough steps planned out to cover the amount of effort they are likely to get before the next review. When I get into one of those rare times when everything clicks and there are few interruptions, I want to be able to get as much done as possible, not stop and fool around with my lists!