Laura & Nancy,
Here's the brochure from last years LI Lighthouse Challenge which will give you the most recent directions to several LI LHs.
Brochure Use the site above for all LILighthouse. You can see many LI Sound LHs by using the ferries, and EastEnd Lighthouse has done a LI Cruise the begiining of June for many years
http://eastendlighthouses.org/fund.htm Email me with any specific questions after using the above resources. You picked a great place to see a lot of lhs in alittle time,
Bob