It depends. And sorry for that… Do you already know which way you want to go? Are you more into self-publishing or are you looking to land one of those hot publishing contracts?
The good news is, if you are aiming for a career as a self-publisher solely (at least for the time being), you most definitely won’t need an agent. Therefore, you’ll certainly need other assistance. Like a cover designer, someone for the layout of the whole book or an editor. All jobs that a Publisher can get done for you if you go by a contract instead of self-publishing.
Therefore, you may need an agent, though. And the reason for that is simple:
Up until a decade or two ago, you’d usually send your exposé to the Publisher of your choice yourself. Or better to a handful of publishers, because chances your manuscript would get picked were rare – even back then.
Over the past couple of years, though, more and more publishers will only consider exposés that are sent in through an agent. Think of this like a firewall kind of thing. Many publishers will only consider books that made it through the first round – the agent.
The agent doesn’t come for free
Now to the bad news: The agent doesn’t come for free. Sure, they do their fair share of work on your behalf but they also take an average of 15% from each book you sell. Given that you’ll only get somewhere around $1.00 per book sale, and the agent will take another 15 cents off of that dollar it’s kind of bittersweet that most publishers require you to send your exposé via an agent.
That means you have to convince not one but two instances. The agent and the publisher.
So unless you already have made a name for yourself, it’s almost always mandatory to have an agent if you want to take the contract route.
Long story short: Ask yourself whether it makes sense to first try your luck as a self-publisher. Even if you don’t get lucky that way, you may collect valuable feedback from your readers before trying your luck with an agent – with a then much better manuscript.