Are you thinking of developing your basement? You might want to check out Mike Holmes article 'This Room Leaves Me Cold ' at the National Post.
Most try use the space in their basement more efficiently. Sometimes we develop the whole basement or just add a new room. Mike Holmes, one the Nation's top renovations experts, concludes, "...when people try to finish the basement they almost always do it wrong ...".
It is something to think about before you try to do-it-yourself or hire a contractor.