There are two or more styles of knitting. The two basic styles are the German or Continental style and the English style. I have done both, but I find that Continental style is faster since one does not throw the yarn around the needle like in English style of knitting. You can read a little about it at Martha Stewart site. Basically, it is a matter of personal preference on which styles you use. The one big point is it is helpful to know both when doing colorwork knitting like intarsia knitting. After you cast on 10 to 12 stitches you can practice both styles of knitting and see which one is more comfortable for you to do. When knitting it is an advantage to do a practice swatch to check your gauge and practice your tension. You can knit every row to make a basic scarf. Knitting every row is called the garter stitch. Most beginners begin with the English method before doing Continental method. It is up to you what style you use. As always have fun and practice both sytles.
English Method
To get started, watch the video below where the Single or Thumb Cast On method is used and then the English Style of knitting. Just remember that the number of stitches you put on the needle makes the width of the scarf.
Below is a video with Long Tail Cast On and Continental style knitting
Recently, I pulled out a wool sweater and a scarf and discovered that they both had holes. The video below shows how to repair holes in your knitting. Notice the break in the yarn in the video.