The normal evolution a fly fisher goes through usually includes fly tying sometime after the first year or two. Some take up fly tying to cut the costs of all the flies they seem to leave in bushes and trees everywhere they go. Others want to try it to increase their involvement in the finer details of the sport. No matter what your reasons are, tying flies seems to be an integrated part of the whole fly fishing picture.
There have been perhaps more volumes of books and articles written on the art of fly tying than any other aspect of fly fishing. If you subscribe to any of the fly fishing magazines, you have encountered articles that included fly patterns. In fact, a few magazines are dedicated to the art of fly tying. Those magazines will enhance the information you find here and I encourage you to consider subscribing to one or two.