Let's start by talking about the contract a bit. Just like every agent is different, the contract for each agency is going to be slightly different. However, there are some pretty standard items. For example, the contract outlines what the agent's role is and what that is worth (the commission). The wording will all be different, but your basic contract will describe an agent working to sell your book to a publisher to the best of their ability.
What does this mean? It means, an agent is going to try their darnedest to find a happy home for your book. Don't forget, an agent doesn't get paid until your book sells*. But remember, this is a two way street. If an agent has exhausted their resources and still can't find a publisher, eventually, they will need to set this book aside to work on other projects. And so will you.
So, what's not in a contract? A contract is generally not going to outline any of the pre-submission work that goes on before your masterpiece gets sent out to publishers. This is where it's important to ask a lot of questions during "the call" and even before that, when researching which agents to query. Maybe you don't want an agent who is going to give you editing notes. There's nothing wrong with that unless you're signing on with an agent who likes to have a heavy hand in what goes out on submission.
Also, not in the contract, is any post sale work the agent might do. Generally speaking, once your book sells, an agent's job is done until you're ready with the next manuscript. I think this is the most surprising thing to new writers. Many think it is an agent's job to work on promotion and are surprised to learn that their agent isn't going to submit their book to all the major presses and nominate it for all the awards.
Once again, this is why those early conversations are so important. Many agencies like to help with promotion. After all, the better your book does, the more money you both make. And every agent wants your book to succeed. However, some agents don't have the time and/or knowledge to be able to help with marketing and promotion. You need to know all this going in.
Keep in mind, there isn't a wrong or a right way to all of this. Some writers want an agent who is going to take their manuscript, untouched, send it to the publishers, finalize the contract and then step back. Other writers want an agent who is going to work through three revisions drafts before submission and then help with a blog tour and press releases. Neither one is better or right, they are just different approaches to doing business and fulfilling a client's needs.
So don't be afraid to ask questions. Don't assume it is going to insult an agent if you ask for client references. Don't guess that the way one agent does business is going to be the way another one does. Asking questions, getting the answers, and making a decision that is right for you shows an agent that you take your career as a writer seriously. And that's sure to make all agents (and writers) happy.
For those of you readers who have an agent, what was the most surprising thing you've learned about the process so far? For those of you still in the query trenches, what are some questions or concerns that you might still have?
*If a contract outlines payments due to the agent that are outside of the book selling, run very far away as fast as you can. A solid agent will not charge you a reading fee, editing fee, copying fee, or any other fee that they can think of in the process of selling your work. You should never be the one writing a check to the agent. It should always be the other way around.