Why this is a mistake: If you’re a type-A personality, publishing just might beat that out of you. You can’t make anyone do anything faster than they’re going to do it. Trying to push agents or editors to work faster than they’re planning on working can only earn you a negative image. Calling every day to check on a submission isn’t a good idea. In fact, it’s a terrible idea. While the saying is that the squeaky wheel gets the grease, in publishing it’s more likely the squeaky wheel gets tossed in the trash bin.
The solution: Let people do their jobs. Your job as the writer is to write. Let agents agent and editors edit. That isn’t to say you shouldn’t stay on top of things and check in, but don’t be excessive and irritating about it. This also isn’t to say that when you get a window of opportunity you shouldn’t leap. Every once in a while, something may appear. If you have an excellent one-on-one meeting with an agent at a conference and she wants to see your manuscript, don’t wait a year before sending it in. I watched a TV show season finale the other night that had a lot of similarities to a series of books I have the rights to, and I immediately e-mailed my agent to see if there was something we could do as cross-promotion. Odds are nothing will come of it, but when opportunities do present themselves, jump.