Lake charts like Bizer have numerous wreckage/dive sites marked. A quick search on this forum will also provide explanations on what your find at each location.
http://www.winnipesaukee.com/forums/...ead.php?t=5836
http://www.winnipesaukee.com/forums/...ad.php?t=10628
http://www.winnipesaukee.com/forums/...ad.php?t=11441
http://www.winnipesaukee.com/forums/...ead.php?t=9904
I would also suggest Roberts Cove for some nice shallow natural rock formations, boulders, etc.
Let me know if you find my keys....