Side views tend not to work the same way as front and three quarter views, as shape of the nose and chin have to be shown in more detail. I found that the method generally used for the other two views doesn't generally work for sideviews, and that there doesn't seem to be any other widely used methods, so I designed my own way. (Don't kill me if it doesn't work for you). The circle and horizontal lines still represent the head and eye line. The vertical line marks the back of the eye and the chin.
 
  

Using the circle as a guideline for the forehead, and the vertical line to determine the chin, draw in the face. The nose is usually centred on the eyeline (make the nose rounded). The top lip usually juts out further than the nose. There's a lot of little features like the shape of the nose and the way the chin curves that simply have to be learnt by looking at examples and practising.
 
 

Draw the ear centred on the eyeline, and far enough in so that it doesn't go over the boundary of the circle. (You might want to try looking at references for the detail) Draw the bottom of the chin. Sometimes the chin goes all the way up to reach the ear, depending on the angle (or perhaps how the artist feels at the time...). Remember to make the chin rounded and not too deep, otherwise Goten'll look too grown up.
Draw in the eye. As this is a side view, the eye should be narrower than it would look front on. Next, the fringe. Goten spikes tend to point more towards the front when view from the side. He has one spike towards the front that sometimes sticks out over his forehead.
 

Goten's hair still has the distinctive shape even when side on (which is probably against several laws of physics, but hey, this is anime). The hair on the side which is furthest away in the picture is bunched up, and the spikes sit a little higher up on Goten's head.
 
 

And here's the finished fanart. Side views are by far the hardest position to draw the head in (if you're not counting views from above and below....), so don't stress too much if you have trouble with them.