Over on El's webpage that I linked, there is a "Getting Started" page with a list of locations based on skill level.
When you can cast with a skill of 130 (that is including a lure, keep in mind), you can move on to "Alterac Mountains, Arathi Highlands, Desolace, Dustwallow Marsh, Scarlet Monastery, Stranglethorn Vale, Swamp of Sorrows, and Thousand Needles". I know that STV is a good spot for floating wreckage in addition to Oily Blackmouth, Firefin Snapper, and the occasional Stonescale Eel schools.
You'll find some floating wreckage anywhere there are schools of fish -- wreckages have a chance to spawn in any school's place. What's inside depends on the level of the zone you are fishing. The higher level the zone, the better types of cloth, leather, and ore you'll find inside.
By the way, I would recommend skilling up cooking while you are skilling up fishing. The two go hand-in-hand and the cooking buffs are always handy.
I followed
this guide not so long ago on my hunter.
Edited, May 1st 2007 5:04pm by thermalnoise