I need a basic rundown of the economy of the Sheepshead area of
Brooklyn NY. i.e. - What the major economy is, etc.

Well, many residents commute to Manhattan.  Major businesses in
Sheepshead Bay include restaurants and some retail outlets of various
sorts (including at least two bait and tackle shops I can think of),
along with various personal services.  There are several small
fishing/cruise lines and a large Cineplex.  There are also a few
retirement/assisted living facilities.  Much of the business is
concentrated on Emmons Ave. and Sheepshead Bay Rd.  There's not a lot
of heavy industry, but there is water treatment plant nearby.  This is
a very rough overview and I'm likely missing a lot (I'm in Brooklyn,
but I live in Dyker Heights).

http://www.sheepsheadbayhistory.com/