Start off with making a roux. A roux is simple equal parts flour and a fat such as butter. In a sauce pan over medium heat melt the butter.
Next add in your flour and whisk the mixture until well incorporated. Cook and whisk for a few minutes until you have cooked out the raw taste of the flour.
Cheese sauce is not just for macaroni - use it to top off vegetables like broccoli and cauliflower or even asparagus.
To learn more about The Mother Sauces use the link to my article, The Mother Sauces - Bechemel.