It is obvious why you should read before you write. Reading helps you get a general idea of what you want to write about so when you start to write, you don’t get stuck half way through the writing.
The worst scenario when you write about something is when you are stuck with no ideas on how to get the flow going.
This is why you need to read up as much as possible before you write so you have tons of ideas in your head of what you want to write about, how you can write it out and how you should write it.
If you want to write about SEO, of course you need to learn about SEO. You can never conjure an article without knowing the spell.
You can search for more information on the web about the topic you want to write and read up. I am sure it is easy to search for the relevant information you need to know.
Whether printed books or digital books, you can get all the information you need easily.
Remember, when you want to write about certain topics, check out the information and read up before you start writing to make sure you have a good flow of sentences and information you want to convey.