If you are frying sausages on a hot pan then it's very hard to brown them on all sides for a couple of reasons:
- the curved shape will cause it to flop along the curve, they are hard to stand up
- if you do get them stood up only the small area touching the pan will get color
So you are frying on a flat pan you can spend a lot of time messing around trying to get color on the sausages, I personally don't think it's worth the effort and just fry them on the sides they rest on. However, I rarely cook sausages this way, I usually use my broiler/grill. The advantages to this are that the sausages get more evenly browned and that the wire rack I makes it easier to stand the sausages up or down as opposed to side to side.
If you do plan to use a frying pan you could get one with ribs in it which will help position the sausages.