Zug Bug Nymph is a great pattern.  The peacock herl body is a great fish attracting material, especially for rainbow trout. 

I remember using this fly on the Esopus River in New York State and catching several rainbows on it.

Excellent book on how to fish a nymph.

Below are the materials needed to tie the zug bug nymph.  All of them can be purchased directly from Orvis

Orvis Hooks

Peacock Herl & Sword

Small Silver Tinsel

Mallard Flank Feather

Brown Hen Neck