Fly rods

on't let anyone sell you a stiff fast action rod. Long, soft rods are easier for novices to load and unload. With a rod that flexes down into the butt section, it is easier to feel the rod working. (Without getting into the nitty gritty, the slower action softer rod, actually generates more tip speed than a fast action rod, making it easier to cast. Being able to feel the rod loading and unloading helps with the timing of your casting stroke. In the long run, to be able to feel the action of the rod makes you a better caster because there are often conditions where your eyes are elswhere and you have to feel the rod. (And here's a little secret, a long softer rod has the capability of actually casting further, when you need to....)
Fly line. Start out with a floating line. A floater is easier to lift out of the water. It is easier to keep in the air as you false cast, compared to a heavier intermediate or sinking line. The object is to make this as easy as possible for a beginner to get the hang of the technique. The problem that most people have with their casting is that they false cast too much and don't trust the loaded rod to to do the work of shooting the line. A simple exercise that I use with people is to have them strip out enought line so that the shooting head portion of the line is in front of them on the ground or water. an equal amount of line should be on the ground/in your stripping basket or what ever. Lift the line, one false cast and shoot the line. It's quite remarkable what can be done with that one false cast when you really focus on it. Even beginners! In addition, floating line is easier to manage when it's in the water. You can lift it and move it about, as well as strip, enabling you to stay in contact with the fly. Intermediate and sinking lines, once they are in the water they sink and the only way to truly keep in contact with the fly is to strip. If you were plugging, would you want to limit your options for presentation? The same applies to fly fishing.
Flies. No clousers. They just cause hassles for the beginning fly fisherman. Inherently by their design, they are like jigs. Picture trying to cast a jig ot keep it up in the air as you false cast. A simple bucktail or flatwing that is light, and streamlined is a much better way to go for beginning fly selections. Stay away from the big overstuffed opaque flies. They're bulky and heavy and cast poorly. ( I don't fish clousers with a fly rod any more. They're easier to cast and fish with a light weight spinning outfit!)
This thought ought to be familiar turf for you as most spinning rods and casting rods are rated for a range of line weights. Inspite of what the fly rod manuacturers say, fly rods are too. Try out different weight lines on a rod of a given weight rating is right on. Most rods can handle lines up to at least two weights higher than they are rated. So for example, an eight weight, can also handle a 9 and a 10 weight line. Depending on the rod's construction, it may actually work better with a slightly heavier line. I use a 10'-6" 8 weight, and my standard line is a 10 weight forward floater. If a store won't set the rod up for you to try out with several different lines, leave!
A fussy little detail, but it's important, is the balance of the rod and reel as a combination. When you buy a rod, buy a reel that when it is loaded with backing and line, and is mounted on the rod, lets you balance the rod/reel right under your ring finger as you hold the rod for casting. This gets the natural balance point and pivot point inside your hand. It makes for much less fatiguing casting and fishing. Thhis often means buying a reel that is "rated " for a heavier line. In order to properly balance my 8 weight, I have an 11/12 teton rell on it with about 400 yards of backing. (Can you say albie or fb tuna?)
Just my .02. Have fun! it's a whole new world, just as I'm discovering with plugging!