Two years ago, I had no idea what a beta reader was. Years before that, most people didn't know what they were. The huge shift from traditional publishing to self publishing required the responsibility of editing a novel to perfection to shift to the writer.
Want to know how to survive the beta reading process and come out on the other side with a better novel? Then read on, writing warrior! (holy tongue twister!)
Typically, there's a team of individuals who are responsible for making a traditionally published novel shine like the tip of a boot camp instructor's boot.
But self published authors don't typically have a team in place to accomplish that. Instead of the publishing firm hiring out editors for this, it all falls to the writer. And on the way to polishing your manuscript, you should always stop off at the beta reading station for refueling.
Typically, writers go through their manuscript and make it as perfect as they can by themselves. It's never ever a good idea to send a first draft to your betas or any editors. Comb through it and ensure it's something not riddled with huge plot holes, because you can't polish a turd. Spare your beta readers and don't subject them to that expectation.
So after you've made as many edits as you can, your novel typically gets sent to a team of beta readers, you incorporate those edits, and then you send your MS to a professional editor. It's best to send it to the professional editor last as you want most of your big issues dealt with already. You don't want to blind your editor by those horrible mistakes. The editor's focus should be more on giving your novel a final polish because, as a professional, they have tons of insight into how to shape a novel!
If you give them an awesome foundation, they're going to make it even better. If you give them a mediocre starting point, your novel might be able to reach the "awesome" level. You're much more likely to reach ultra-mega-mega-awesome level, though, if you give that professional an awesome draft of your novel to start with.
A lot of people use beta readers even if they don't know it. A parent, significant other, or best friend who reads your work and gives you critiques is technically beta reading. And to be honest, most of us need that person to tell us whether or not we're crazy for taking our story in a specific direction.