You can check out the new york state tourism web site (I think it's called http://www.iloveny.com), and then select Long Island as a destination. Living on LI myself, I agree with Russell - the island is easily 100 miles long - some (okay, maybe most) quite developed - so it depends what you're hoping to see.

The Cold Spring Harbor Laboratory has a science museum and offers great tours. (the dna double helix was identified there, I think!). Also, the area surrounding Cold Spring Harbor is very pretty. You may be able to find a b &b in that area.

Of course, the further east you travel, the less developed it is. The island splits at its tip into 2 forks - north and south. The south fork is the hamptons and the north fork is home to over 20 wineries. both areas are rural.

Re LGA - there are probably more flights into LGA than Islip - but Islip is convenient, too. Either way, you would have to rent a car to get around. Cold Spring Harbor is at least and hour from LGA and 40 mins. from Islip.

How long are you planning to be in the area? If you would like to do a gtg, or need more detailed info - let me know.

best regards, vanessa cutchogue, ny