Go to the tutorial section and click on "New Tutorial". Then fill out the topic and a couple of sentences in the Synopsis ( forget the byline). Then set the Category and off you go to make your tutorial text. It is good practice to structure it into 1. 2. 3.
etc, and bold the numbers. The more structure the better. Brink usually "enhances" it anyhow.
If you want the synopsis to also appear in the post (not only in the tutorial in the tutorial section), paste it in the front of your main body text like this (info)synopsis text[/info] - the brackets in front must be also square. If you have further questions, let me know.
This is how the synopsis will look in front of your text once all brackets are square