StephanieR, I often purchase true bargains that I really like, in 3 to 4 yard cuts. I never use all the yardage in one quilt. Even a two color quilt does not use that much yardage of a single color. But a three yard cut will for sure give you enough for one quilt and some left over for another quilt. Oh, I should mention that you may use more of the fabric if you are making the binding out of that color or a really large quilt such as a queen size. In the end, 3 to 4 yards is just a nice easy amount but no rules apply. I hesitate to buy only 1 yard. I fear I may run short. As you make more quilts you will begin to know your own style of quilt, size of quilt and how much room you have to store extra fabric and scraps.
Have fun with quilting and ask all the questions that pop into your head. Everyone here was once a newbie! There are so many really skilled and helpful quilters on the Quilting Board (QB) site of all ages. Take advantage of the experience of our members.