Start combing to the sides anytime. As soon as the hairs are long enough to hold together with product, you can start experimenting with different waxes or other products. No two guys are the same, so I cannot tell you what product will work best for you. Some guys will have a natural handlebar style and will have little need of product. It will get difficult so a time period, but then will get easier with length.

My Beard Journey:  http://jefffsbeardboard.yuku.com/topic/25137/Finally-I-have-a-Beard
Beard and Bald Thread:  http://jefffsbeardboard.yuku.com/topic/27831/Beard-bald-head-shaved-head-or-buzzcut
Patchy Beard Success Stories:  http://jefffsbeardboard.yuku.com/topic/33742/Patchy-Beard-success-stories-Before-and-After-photos#.ViujbH7nuM8
Taming the Wild Mustache:  http://jefffsbeardboard.yuku.com/topic/30822/Taming-the-Wild-Stache#.Vj_Mh7erTIU