First of all find yourself a copy of Boyd Pfeiffer's book Shad Fishing
. You won't be sorry.
There's a commercial shad fishery in the town where I grew up but I was never much of a shad fisherman myself. The reason being that there was no wadeable spot with the proper structure. I think that's the toughest thing about shad fishing. Shad can be very structure oriented, be that rocks and abutments during the spring run or cool holes in the summer. Reading the water is as important as in trout fishing. Plus, where's there's good fishing there's usually a crowd too which can make fly fishing even more difficult.
They run in the spring when the dogwoods are in bloom and mostly on cloudy days and at night. They're very sensitive to daylight. That same brightness has an effect on the type of flies you use also.
The fishing itself is pretty basic. It's just like fishing a wet fly or streamer with a cast down and across followed by a slow jerky retrieve. The most important aspect I think is casting from the right spot to get the proper swing.
The fly selection can be madding, with the right colors changing from day to day, hour to hour, or even every few minutes.
Here's a picture of some shad flies from the H&H website. As you can see the tying is pretty basic. It's most important IMO to have a good variety