Keep in mind I self-publish fiction, but I _think_ most of this will be applicable to non-fiction as well:
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* The Playing Field *
Self-publishing these days has a very low barrier to entry. At the same time, the quality expectations for indie authors are high. Some genres are still niche enough to make readers more forgiving of bad editing or bad covers, but books in more popular genres (thriller, romance, etc) really need to match the quality of traditionally-published works. Self-publishing used to be something associated with people who couldn't get traditionally published, but now even traditionally published writers are going indie or hybrid because traditional publishing deals are often crap and self-publishing can earn them more money and give them more control. In other words: there's a lot of really good competition.
-----------
* The Writing *
One of the first things to do is pick a genre and a niche within it. Then, see what is selling in that niche and where. See what kinds of covers are generally used in best-sellers within the niche, what POV they're written in, etc. That can get you started with the actual writing part.
Keep in mind that in the self-publishing game, the most important part is to actually write and _publish_ things. Build a backlist. It is very, very rare for an indie author to suddenly blow up and be successful with one book. For many (most?) authors, most income comes from the backlist. In the traditional world we often hear of authors taking years to write their masterpiece. In the indie genre fiction world, it is common to publish multiple books per year.
-----------
* Kindle Unlimited vs "Wide" *
Then, you'll need to decide if you want to publish in Kindle Unlimited or go "wide". KU requires Amazon exclusivity for ebooks, and authors get paid per page read. Some genres do _especially_ well in KU, like romance. There are indie romance authors who make the bulk of their six or seven figure incomes in KU. On the other hand, Amazon exclusivity is a tough pill to swallow for some - being dependent on one company for all of your ebook income can be scary, which is why I chose to go wide even though I publish in a traditionally KU-leaning genre.
Your book is enrolled in KU for 3 months at a time, so it's not set in stone - you can pull your books out of KU if you want to change strategy later.
-----------
* The Platforms *
To publish on Amazon, create an account at http://kdp.amazon.com. Remember that you can only have one KDP account at a time - creating more than one account can get your whole account banned, so be careful. Once there, you'll be asked to fill in your tax information and then you can go through an online form to list your first book. This is also where you'll pick if you want to be in "KDP Select" (which translates to KU) or not.
To publish wide, you'll be dealing with five major retailers and a bunch of smaller ones. Amazon, Barnes & Noble, Apple, Google, and Kobo.
Many authors try to go "direct" with the big 5 above. That is, create a publishing account at each of them and create separate listings through each platform. For other, smaller storefronts they go through a distributor (like Draft2Digital). Distributors take an additional cut of your royalties for their trouble. Some prefer to do EVERYTHING through a distributor and eat the cost, since it's just more convenient than managing listings on multiple platforms. I'm direct with KDP, Google, and Kobo (and my own direct store), and use D2D for the rest.
Just starting with one platform and then branching out is always an option, too.
-----------
* The Pricing *
Pricing will depend entirely on your genre and book lengths. You'll need to see what others in your niche are charging and follow suit. Also, keep in mind that most retailers have royalty percentages that are dependent on your price. For example, at Amazon you get 70% of the book cost if your book priced between US$2.99-9.99. Every other price point below or above that gets 35%. Also seep in mind that the major distributors have contract clauses that state your pricing has to be equal on all storefronts. So you can't charge $2.99 on one store and $5.99 on another.
-----------
* The Marketing *
For marketing, the most important part to start with is nailing your passive marketing. That means your book cover and blurbs. Look at what others that are selling in your genre are doing as examples. Additionally, start a newsletter as soon as you can. They _do_ work for indie authors and they _are_ important. It's the only line you'll have directly to your readers that is not contingent on a social media algorithm or some other middle-man.
-----------
* The Playing Field *
Self-publishing these days has a very low barrier to entry. At the same time, the quality expectations for indie authors are high. Some genres are still niche enough to make readers more forgiving of bad editing or bad covers, but books in more popular genres (thriller, romance, etc) really need to match the quality of traditionally-published works. Self-publishing used to be something associated with people who couldn't get traditionally published, but now even traditionally published writers are going indie or hybrid because traditional publishing deals are often crap and self-publishing can earn them more money and give them more control. In other words: there's a lot of really good competition.
-----------
* The Writing *
One of the first things to do is pick a genre and a niche within it. Then, see what is selling in that niche and where. See what kinds of covers are generally used in best-sellers within the niche, what POV they're written in, etc. That can get you started with the actual writing part.
Keep in mind that in the self-publishing game, the most important part is to actually write and _publish_ things. Build a backlist. It is very, very rare for an indie author to suddenly blow up and be successful with one book. For many (most?) authors, most income comes from the backlist. In the traditional world we often hear of authors taking years to write their masterpiece. In the indie genre fiction world, it is common to publish multiple books per year.
-----------
* Kindle Unlimited vs "Wide" *
Then, you'll need to decide if you want to publish in Kindle Unlimited or go "wide". KU requires Amazon exclusivity for ebooks, and authors get paid per page read. Some genres do _especially_ well in KU, like romance. There are indie romance authors who make the bulk of their six or seven figure incomes in KU. On the other hand, Amazon exclusivity is a tough pill to swallow for some - being dependent on one company for all of your ebook income can be scary, which is why I chose to go wide even though I publish in a traditionally KU-leaning genre.
Your book is enrolled in KU for 3 months at a time, so it's not set in stone - you can pull your books out of KU if you want to change strategy later.
-----------
* The Platforms *
To publish on Amazon, create an account at http://kdp.amazon.com. Remember that you can only have one KDP account at a time - creating more than one account can get your whole account banned, so be careful. Once there, you'll be asked to fill in your tax information and then you can go through an online form to list your first book. This is also where you'll pick if you want to be in "KDP Select" (which translates to KU) or not.
To publish wide, you'll be dealing with five major retailers and a bunch of smaller ones. Amazon, Barnes & Noble, Apple, Google, and Kobo.
Many authors try to go "direct" with the big 5 above. That is, create a publishing account at each of them and create separate listings through each platform. For other, smaller storefronts they go through a distributor (like Draft2Digital). Distributors take an additional cut of your royalties for their trouble. Some prefer to do EVERYTHING through a distributor and eat the cost, since it's just more convenient than managing listings on multiple platforms. I'm direct with KDP, Google, and Kobo (and my own direct store), and use D2D for the rest.
Just starting with one platform and then branching out is always an option, too.
-----------
* The Pricing *
Pricing will depend entirely on your genre and book lengths. You'll need to see what others in your niche are charging and follow suit. Also, keep in mind that most retailers have royalty percentages that are dependent on your price. For example, at Amazon you get 70% of the book cost if your book priced between US$2.99-9.99. Every other price point below or above that gets 35%. Also seep in mind that the major distributors have contract clauses that state your pricing has to be equal on all storefronts. So you can't charge $2.99 on one store and $5.99 on another.
-----------
* The Marketing *
For marketing, the most important part to start with is nailing your passive marketing. That means your book cover and blurbs. Look at what others that are selling in your genre are doing as examples. Additionally, start a newsletter as soon as you can. They _do_ work for indie authors and they _are_ important. It's the only line you'll have directly to your readers that is not contingent on a social media algorithm or some other middle-man.
Good luck!