Oh how dreadfully annoying! I was just answering a comment asking about pool sessions & Haloscan lost all my links & nice explanations & all (ok, actually that's not that annoying, it's an anti-spam feature. Well, here's a quick n' dirty version.
Sebago Canoe Club (my club!) is running Sunday afternoon pool sessions in Flushing Meadows Park. Full details & contacts on Stevie's >Kayak Brooklyn.
The Appalachian Mountain Club's CT branch kicks off their >Sunday morning Greenwich YWCA pool sessions this weekend.
Those first 2 sessions have some small cost to cover pool rental - usually $20 - $25 I think, but I can't swear. Both are bring-your-own-boat, and the instruction is volunteer & informal, but people are generally willing to share both their boats & whatever level of expertise they've achieved.
Downtown Boathouse runs a pool version of their popular public programs at Riverbank State Park.
Possibly free, or at the very least very low cost. Again, it's volunteer instruction. Equipment is provided at this one.
If you're interested in a more formal, intensive learning experience, check out >The Small Boat Shop's winter classes.
Those are the ones I know about off the top of my head!