Assuming that you have written the best manuscript you can, that it has been completely vetted through your critique group and some fresh beta readers, then you might be ready to seek representation. This is not the only way to go, but I think it is the best way for the majority of writers.
Looking for an agent is easier than it has ever been before because everything is on the net. The main thing is to do your homework. It’s great if you can attend conferences and talks where you can meet the agents in person, or at least listen to them speak. But if that’s not practical, you can also search for videos and/or written interviews. Also read sites like pubrants.blogspot.com and follow the links once you’ve read all the sample queries and excellent posts about getting an agent.
Look at queryshark.blogspot.com and agentquery.com and “writer beware.” Read Chuck Sambuchino’s excellent advice and stories from agents. Give yourself a month or so to do your research before you query both established agents as well as new, hungry ones at established agencies.
You might be in the rare position of having a personal recommendation to another writer’s agent. This would come because a close friend volunteers it (you never want to put a author on the spot by asking). All you have to say to a writer you personally know is that you’re going to be submitting to agents. If they want to recommend you, they will offer. If they don’t, it’s probably because they know their agent isn’t taking new clients or is not interested in a particular genre at that time. They might have too many authors working in that arena, even if their want list hasn’t been updated to reflect that.
A caveat, because I’ve seen it happen. You do not want to be that person who stretches the truth and represents themselves as “friend of author x” or “recommended by author x” unless you do have permission. The publishing world is small; everyone knows everyone else, and with private messages via social media, your reputation can be blown in a day. So be honest. It’s for your own benefit.
Once the agent has your full manuscript, then you wait. A response can come as quickly as a few hours, but the more typical time frame is weeks or months. You should also querying other agents.
Once you have one agent who offers to represent you, the courteous thing to do is to email each agent who has your full. And you put in the subject: “Offer of Representation.” That gives them a head’s up and they will often put your manuscript at the top of their pile. Don’t try faking this, it only works if it is real (see paragraph 4 above). In the email, you explain how one agent has offered representation and you wanted to give them the courtesy of knowing. Do not mention the name of the agent.
Now agent #2 (and 3, etc.) have the opportunity to either let you know that they are in the process of finishing reading your manuscript or that they would also like to make an offer of representation. They might ask you for a few more days. Or they may say they wish you well. But by doing it this way, you have handled this professionally and have not burned your bridges. The agent you are turning down today might be an editor you’ll want to work with next year.
What agents dislike is to suddenly get an email saying that you have accepted representation elsewhere, without any other discussion, while they may have invested precious hours reading your manuscript. By giving them this courtesy, you’ve shown everyone that you are a professional. Here’s what an respected agent has to say:
The agent who may be perfect for one author may not be the one who is perfect for you. It’s a bit like a marriage. That’s why you need to do your own research and come up with a list of possibilities. Some conferences have actual speed dating with agents. Evaluate an agent based on your specific chemistry, how you click, your needs and goals – not someone else’s — so you can find your perfect fit. If you don’t get any responses from your query, consider rewriting the query. Don’t expect any notes from the agent; that’s not their job. Consider starting a new manuscript so you’re always moving forward. I believe that when you are ready, the agent is there. Good luck!