Congratulations on your offer!!
Here are some questions it may be good to have the answers to:
- Does the agent sell what you write? Nonfiction and fiction sometimes require different editorial approaches, not to mention different editors. Be sure the agent is comfortable working with and selling books like yours.
- What is the agent's submission plan? Does he/she feel the manuscript ready or not? If so, where do they envision sending it and how will they pitch it? (This will give you an idea of how they're thinking of your book, and you can decide if that aligns with your vision.)
- Is the agent interested in one book or representing you over multiple books?
- What's the agent's communication style? Do they prefer email or phone and how often are they in contact with their clients? How soon can you expect to hear back if you have a question about something? (Knowing what to expect in terms of responsiveness is really important for your sense of security and trust in your agent)
- Does the agent/agency do anything to support their writers leading up to and during book launches?
- You should ask for a copy of the agency agreement to review, and you should also ask for a week to let other agents with your full/partial know about your offer and decide whether they are interested. And if you have pending queries with agents who are top choices, you can contact them too and tell them you have an offer.
- Read the agreement carefully and make sure it all makes sense to you. Ask about anything that's unclear, and the agent should gladly explain it to you. Make sure they're charging standard rates for standard services and not overreaching.
- Does the agent really LOVE your manuscript and your writing? (This is one to answer on your own, but it's of huge importance. It means the agent's not going to give up easily if it doesn't sell right away; and they're likely to get equally excited about other things you write, too.)
- And you've checked the agency and agent out in the Bewares section? If there were any negative comments about the agent, take note of them and consider whether you might experience something similar.
I hope that helps. Good luck!