Writing a book is not a something you can do quickly. But it's no magic in the Internet age. You can benefit from the collaboration and engagement of early fans or interested people.
First outline a first, rough view of the story you want to tell. Beginning, ending and the side story, that will hum in the background all the time. Most failures in the content of books is that the authors are not keeping the story line and get lost in the sea of words. Try to focus on the "wireframe" you made before. If you are blessed with an extraordinary sense of staying at the topic over month of work, you probably won't need to do this. But it don't do any harm if you have a basic framework.
Do a character relation diagram if you have more than a very few characters in your novel. That will keep a clear line, and can save a lot of time. And you will be very, very thankful for that diagram, if you ever plan a new chapter or episode, based on the original book.
One of the biggest problem for non-native English speakers, is what language to choose. If you want to use your own language, keep in mind that English is readable in much more countries. So your audience is much, much bigger. The world is yours if you write in English. Which brings us to another problem. Even if English is your first language, it might not be enough to use it to write a proper book. That might getting worse if it isn't your native language. But do not fear.
Remember, there are a lot of people on the net that can correct your work. Try to engage people in your work. You could publish your early version as a Wiki. Or in a blog and people could comment, telling you about grammar problems. Another great way is interaction in social networks. Engage people from there to read through your chapters. Every feedback should be welcome.
At least you can keep in mind that bad English is understood by more people, than the best work in your own other language.
If you think your book is ready to be published, try the new ways. You can easily publish an eBook at Amazon or other platforms if you want to make money with your book. Don't let the community down. Name the contributors in your book, and choose a license that allows you to use the contribution from people commercially. That's the payout for their engagement. If you want to publish your book for free, you can still consider Amazon to publish it, because you reach a big audience. As a free book, people are ready to try reading your novel. But you also can release it on your website. Do not rely on a single format. You should at least publish an ePub and a PDF version. A HTML version would also be a good idea. People can easily send those formats to their Kindle (converts automatically via Kindle-Mail) or any popular eReader, smartphone or tablet.
Keep remembering, the Internet makes it ridiculously easy to publish your work. You still have to do a lot of things and don't get frustrated from setbacks or bad comments. Try to focus at the positive. Do it, learn from it, work with the community and consider a free license, like a Creative Commons License, to protect your work, and still be able to benefit from the open work of the Internet.
And now, let's write something...