For those that been not crocheting for long, learning new techniques and stitches can be a frightening endeavor - one that is often avoided entirely because a clear path to success is frequently not clear and available. This is especially true of learning how to crochet the shell stitch, a technique that looks unbelievably difficult but in reality is easily achievable in short time with a good tutorial that embodies a sound lesson plan. It is important to show patience even if your personality falls more on the side of instant gratification, keeping in mind that anything worth knowing takes a little time and a lot of practice.
Learning how to crochet the shell stitch is best digested in small bites, practicing following along with a tutorial for 20 or 30 minutes and then taking a break for several hours to wrap your mind around what you just saw and did. Go back and forth in this manner a few times and you'll begin to get the hang of it in a day or two and within a week you'll be creating projects you only admired wistfully in the past.
Here are a few of the better free tutorials on learning how to crochet the shell stitch, it is recommended that you view each in full to get a good overall feel how to make the stitch and what types of projects you can incorporate it in:
At http://crochet.about.com/od/learntocrochet/tp/how-to-crochet-a-shell-stitch.htm there is a very good written tutorial on how to crochet the shell stitch that offers clear instructions, a ton of photos and sound general information that is useful.
At http://www.allfreecrochet.com/Tutorials/How-to-Crochet-a-Shell-Stitch there's a brief tutorial on how to crochet the shell stitch that covers the basics quickly and gets straight to the point.
Here are a few outstanding videos on how to crochet the shell stitch that can be paused, reversed and watched as many times as needed to grasp the lesson: