Hey guys! I recently started looking into publishing some e-books through Amazon. I've read multiple articles from Amazon and other sources, but I can't find a catch. Are there any downsides to using KDP? What do you guys recommend, like/dislike, and what is your best advice?
Joseph already posted the top three things that are important.
The only thing I would add is this: be realistic. There are millions of books on Amazon's website and yours will have to stand out if you wish to get sales. There are no shortcuts. Take the time and put out a great product and think long term.
I recommend you get the Smash*words formatting guide and read their marketing guide as well. Both are free. Keep in mind, the marketing advice might be out of date, but it's a great place to start.
Another good starting point is Joe Konrath's Newbie's Guide to Publishing (website) and The Passive Voice (website).
Kboard's writer's café is another place to get good information.
Good luck and welcome to KDP
ETA: Things change FAST in self publishing, so you need to get a handle on the basics and then learn what has changed and what that means for your business.
The only catch is the obvious one, that you may become frustrated and disappointed. What most people don't understand is that you're also taking up the mantle of publisher. The best writer in the world may be the worst marketer. You're not only in competition with every other writer in your genre, but every publisher, from single-title small presses to professional publishers with millions to spend on development, design and marketing.
You can best help yourself with some mostly common sense actions:
Hone your craft before you publish
Learn the ins and outs of book design
Teach yourself formatting (or hire someone)
Become knowledgeable about the publishing industry and bookselling
Study the marketplace and your competitors
Give readers the best product you can, written for them, not you
And, lastly, aim high, hope for the best, and don't give up.
I recommend that you stay clear of the Kindle pooh traps, including Kindle Select and KDP Print Beta. Sell to all possible outlets through Draft2Digital (some people swear by Smashwords, though I don't care for it).
For paperbacks, you'll do much better at IngramSpark or CreateSpace.
And yes, temper your expectations. It's much harder to make money here now than it was five years ago.
You might read the third post on my blog.
(Don't trust KDP to publish a print edition. Don't trust CreateSpace to publish an ebook. Each does one thing well and the other thing poorly.)
Be as clear as you can as early as you can about what exactly it is that you want to get out of writing and self-publishing.
If you want to write for self-expression, or for artistic reasons then great – that is a perfectly legitimate reason for writing and publishing what you write. But be advised that your book will almost certainly not sell unless, by some wild stroke of chance, your self-expression happens to dovetail with an existing hot selling market.
If, on the other hand, you wish to sell books and make money then - before you write a single word of a single book that you hope to sell and make money from - you have to study the markets. There are various genres, sub-genres and niches within the Amazon Kindle market in which newbie indies prosper. It is your mission to locate these markets and then provide the content that they demand.
Be not confused. Be clear in your own mind what outcomes you want, and be clear about what inputs are required from you to achieve those outcomes. And thereby avoid the confusion, disappointment and sheer finger-biting frustration that is often the lot of the newbie, (and sometimes not-so-newbie) writer.
Good luck, whichever path you choose.