If you're talking about a scatter plot (also known as a dot plot), the most easy way is to find all the points, and then order them. When you finish ordering them, cross out one on each side until you reach the middle number.
If you stop on two numbers, do this:
Add those 2 numbers.
Next, divide them by two.
THERE YOU GO, YOU FOUND THE MEDIAN. :)
Good luck with your studies. :)