Joseph Fusco
<a href="http://fusco-verga-const.com">Fusco & Verga Construction Co., Inc.</a>

Just to lead you in the right direction.
As a rule of thumb only: If the joists above
and below the wall in question run parallel
to that wall, it is PROBABLY not load bearing. If the joists run perpendicular to
the wall in question, it is PROBABLY a load
bearing wall. The only way to really verify
this is to physically look at the joists-
which may require the opening of ceilings. I
have seen many homes that were remodeled
(example: the lowering of ceilings) and had
total disregard for walls being bearing or not. Much of my work is dealing with distressed homeowners who have floors and houses in near collapse, so, if you have any
doubts about your ability then take Joe,s
advice and hire a P.E. Good Luck!