Keeping a website is time-consuming, your site may remain obscure, your pages will become outdated, and eventually you'll probably quit writing anyway. So why bother?
Because regular writing helps you to learn things deeper, helps you to spread your ideas, and helps your readers learn faster too—or at least have some fun.
There are many other means of communication nowadays, but writing is one of the most powerful, accessible, and scalable. Words are magical. You can write something today and people might read your words years later. Almost anyone can download your pages and read them. Even over a slow internet connection, on a slow computer, with a small screen: Nothing can stop your words. The number of your readers is unlimited, and the delivery cost is close to zero (less than one US dollar for a million page views).
You may say that writing is hard. Yes, it is hard, especially if you are writing in a foreign language, but with practice your writing will get better and the act of writing will become much more enjoyable.
Probably the first question you'll ask yourself is, what should I write about? You might say you definitely have nothing special to say, all your thoughts are obvious and all your stories are boring. But something that is obvious to you is not always obvious to other people, and something that is boring to you might be fascinating to someone from a different culture or who is new to the topic.
Tell a story about a project you are working on. It can be useful or entertaining, or both. It can be about a thing you made this week or a thing you learned today. You can write about how and what you are doing, and why you are doing it. What problems you are solving, how you pick and configure your tools, and so on.
In my case, today's story is about restarting this website and writing the first post. Way too meta? True.
If you want to make your website useful, make your pages actionable. Each of your posts can be a step-by-step instruction, a recipe. Start with small, simple pages and add depth gradually.
After choosing your topic, the next hard thing is to keep writing. To make your new hobby sustainable it is wise to build a writing habit—and most importantly, a publishing habit, or you may end up with hundreds of unpublished drafts. To fight your perfectionism set up a schedule: collect notes during the week (or better tweet as you go) and then on weekend repackage those notes into a structured page to publish it on Monday.
Just keep going.