A lot of publishers only take agented submissions. Getting an agent is not easy--I have 65 rejections to attest to that one. There are a ton of scams out there--and they are so crafty that many writers fall for them--then realize too late what it was.I have heard the easiest way to get an agent is to have a pending offer from a publisher--certainly this would be easy. Just call and say I have an offer--an agent would be a fol not to take you on at that point, you've done their work for them already.
But the process of finding a publisher--getting out of the slush pile, is no easier, and I think more difficult than finding an agent.
With my first book, several years ago, I sent to publishers. Most stated no simultaneous submissions, so it was a one at a time process. Most still state no simultaneous submissions. At that time very few said no unagented submission--most now say that.
Anyway, I sent to one or two at a time and spent 3 years trying to find a publisher--no dice. How many publishers did I go through--I think 10 or 15 IN 3 YEARS!! Ouch.
I spent 4 months looking for an agent for my latest book. Once I sent the initial query to Zack it took 90 days from first letter to contract.
We spent several months doing intense editing.
NOW that he is pitching the book--well it has gone something like this, he sent out queries--a large number of them. Simultaneous submissions is not the same as simultaneous queries. With a a few days he received a large number of requests for the complete ms. WOW--OK no one at a time, no send sample chapters, simply yeah, send me the whole thing.
We've gotten rejections on the ms, BUT and note the big BUT, they took days not months and in some cases a year or more.
A good agent can do wonders, a bad agent can tag a sticky on your back that will follow you forever.
Your agent should be a member of the AAR, and the golden rule is money flows to the writer not to the agent or publisher. There will be fees for postage etc., but this you would have if you were doing it on your own. Very few publishers accept ms via e-mail, yet from an agent many do--a great savings.
Working with an agent can be difficult--they understand commercial fiction. I have heard from others working with agents that they got 10 page or longer editorial letters. I got a one page letter, I was lucky. These are not like critiques in a crit group--they give you an idea of the changes needed, but unlike a crit group, you have to seriously consider these changes, every one of them. And if you decide you don't like one of them, be prepared for a long phone conversation which will in all likely hood end up in the suggested changes happening.
And editor at a publisher is going to be even harder to deal with in the form of changes--make these changes instead of you may want to make these changes.
Do you need an agent--no you don't. Not if you have a lot of time to devote to sending and waiting, and you don't care that you can't send to more than half the publishing houses, and if you don't care that your sub will go to a general admissions editor instead of land on the desk of that one editor "who loves this kinda stuff." Slush piles take time. A good agent skips the slush pile.
IMHO and experience,
Shawn