The shad run is from April/May in the Trenton/Lambertville, NJ/ New Hope, Pa area and from late May - early June up near Narrowsburg and Callicoon, NY.
With all of this high water in the Delaware River, it's kinda' tuff to pick out the deep channels, but as the water levels drop, look for the main channels - The fish really move through these channels in early morning and a few hours before dark, but can be caught all day long. Look for a channel that comes close to the shoreline, or you'll have to do some wading to get within casting distance of the main channel.
I like using pearl colored darts w/flourescent pink or flourescent green tipped head area, but I also carry red/white darts, red/yellow darts, lime green/white darts, silver darts, and gold darts. Best bet is to go to a bait and tackle in the area you're fishing and ask what is the hot color for that area. Also, ask some of the locals that are fishing for them. Most are more than willing to give up info., as this is an underfished fish resource that is really a lot of fun.
Kinda' like fishing for trout in a river, cast the dart slightly upstream in the channel and give it a few twitches on the way down stream. At the end of the drift, wait a few seconds and give the dart a few light twitches. I've caught a lot of shad on the end of the drift.