As a new knitter, I wanted nothing to do with seams; I was eager to get my finished garment as quickly as possible. There are many designs that eliminate the need to seam, so I wasn't limited in the projects I could knit. As I became more comfortable with my ability as a knitter, I began exploring the use of seaming-and it turns out seaming isn't so bad. Seams give your garment more shape and add strength to high wear areas.
Like any technique, there is a method to it. When seaming horizontally (one row across many stitches), I use a tapestry needle and work with the right side facing me. I start in the row below the seam, come through the center of my stitch (from the back side to the front side), around the corresponding stitch in the row above the seam, then back into the center of the same stitch on the lower row (from the front side to the back side). The working yarn then comes one stitch over (across the back side), and the process repeats until I've seamed all the way across and the ends on either side are woven in. Essentially, I'm following the path the yarn would have taken had it been knitted, similar to the concept of grafting [the difference being that grafting in worked into live stitches].
So, seaming may not be something you utilize every project, but you certainly don't have to fear it.