Fly Rod Selection is important and based on the type of fly fishing you are going to be doing. Wading or floating? Dry fly or nymphs? Big water or a small stream? Or maybe a combination of them, your fly rod selection could matter.
Fly Rods come in a very wide variety of sizes and types. For the most part today's fly rods are made of some type and technology of graphite these days. Although there is currently a resurgence of fiberglass, can you say "retro", why I don't really know.
While I primarily fish a graphite fly rod, there is a time and place to break out my Bamboo Fly Rod. I love the feel of a nice bamboo rod, but for working out of a boat and big water I depend on my graphite fly rod.
All fly rods have what is known as an 'Action', typically Fast, Medium, or Slow. Fast action fly rods typically bend mostly in the tip section of the rod. Fast also means it is a quick rod and throws tight loops, mostly for fishing spots as you scoot by in a boat, it can go quick sometimes. Pick up your line, turn it over and hit the next spot. I prefer a faster rod for floating to capitalize on as many spots as you can hit.
Medium action is for fishing when you have more time to fish a particular run but there is no hurry and you will have plenty of oppurtunity to hit the sweet spots. Medium rods will flex more towards the middle of the rod but before the cork handle.
Slow action fly rods are usually close to the way a bamboo rod would feel. Slower, softer, bending down into the cork you can almostbecome part of the rod. I think of it as bringing the beauty back into the art form of fly fishing and casting. It reminds me of a article in newsweek called 'Zen and the art of fly fishing'.
For Wade Fly Fishing around here on the Roaring Fork River & Colorado River, I prefer a 9' 5wt rod, for the most part, and something fairly fast. This way I can throw dry flys or switch over to nymphs if the bugs aren't hatching. On my home waters the 9 foot fly rod will allow me to reach across seams and faster water to find my targets. It is also handy on the Frying Pan River unless I am strictly targeting a dry fly hatch, then I prefer a my 'old style' slow action graphite fly rod, a 7'10" 3wt. It is kick butt fun fishing.