Reddit mentions of The Copyeditor's Handbook: A Guide for Book Publishing and Corporate Communications

First, learn a bit about what copy editors' and proofreaders' roles are in the publishing process. Here's a good primer (it's written for authors but gets the point across).

If you think it's work you could be good at, take a copyediting course. Many local community colleges offer them in person and online. Here is an online course from a school near me. The syllabus is a pretty solid introduction, anything similar would work. I can't see a newcomer breaking into this without a class, because the work is more than just spotting typos and checking grammer, there are a lot of subtle details to be aware of.

In addition to, not instead of, a class, The Copyeditor's Handbook and The Subversive Copyeditor are books you need to have on hand, as references but also to get a detailed sense of the work.

Once you have started learning the job, you can try to find work. It's a very insular field--if anyone wants to DM me for some contacts feel free, but knowing who to ask does not equal getting work. Everyone will send you a copyediting test before hiring you, and some are really picky about reviewing your results. But if you do enough networking, and can get a couple of projects under your belt, you can meet more and more people to work for.

Proofreading starts at around $20-25/hour (assuming you can edit ~12-15 pages/hour) and copyediting starts at $25-30/hour (assuming you can edit ~8-10 pages an hour). Rates go up for rush projects or specialized content (legal proofreading, cookbooks, technical copyediting) so if you already have domain knowledge you can apply then look into publishers for those subjects. Note those rates are gross receipt; you're an independent contractor so you still have to pay taxes out of what they pay you.

Hope that helps! Feel free to DM me if you have any questions, it can be tough to break into it but is a great option to have in your pocket if you can.

Hey, there! My go-to editing guide is The Copyeditor's Handbook. Happy writing!

Amy Einsohn's Copyeditor's Handbook

If you're interested in spending some money on courses, I recommend UC Berkeley Online Extension Professional Sequence in Editing Even just taking the first course on Grammar, Mechanics, and Usage would get you up to speed. I took the first two courses a while back and don't regret it. I'm normally not crazy about online courses, but I received quality feedback there.

Try to enroll in a workshop. If you apply yourself and take them seriously, then you will see your writing improve dramatically.

Purchase writing books, such as The Copy-Editor's Handbook to help you with formatting, etc., which has ruined many an otherwise promising manuscript.

Also, and this may sound pessimistic, but don't plan your hopes and dreams on becoming rich enough off of writing novels. Most writers who are published have to work other jobs. Very few make enough to write full time. Plan accordingly, and have a way to ensure your financial stability so that you DO have time to write without worrying about bills or food.