As a beginner in any programming language, it often helps to have a little cheat sheet, which contains most important infos in a dense way.
So I searched for great C# cheat sheets and would like to share the best ones I could find with you :)
As you are still a the beginning of your C# journey, many of the topics covered in the cheat sheets might look like gibberish to you. No worries, we will cover most of it during the course. 
For now you can simply use the part of the cheat sheet, that you have learn in the course.
This one is very short and to the point.
That one is a little more thorough.
In case you have created one yourself or you found another great one in the web,  and would like to share it with us, please feel free to do so :)