This link, for an article on Poets & Writers, was posted on one of my writer's loops today, and I had to pass it on. It's a behind-the scenes look at what a good literary agent can do for their clients during the period after the contract is signed but before the book is published.
It's a long article - five pages - but I was riveted. I think it's well worth the time to read if anyone has an agent already, is searching for an agent or might be agent hunting in the future. I even think it's a great read for anyone not interested in signing with an agent at all, just to see what other kind of things agents do aside from negotiate the contract itself. Plus it's a good reminder of just how awesome editors are too!