I agree with the other thread. You really need a vector drawing package with connector lines that stay connected as you move things around. Also a library of component symbols is useful. On Windows I tend to use Visio. Also AutoCAD.
For free applications go to the Linear Tech website and download LTspice or SwCAD. These not only have a drawing tool with a library of symbols but have very good simulators. The drawings can be saved and printed.
For Linux there is QCad. Also look at Inkscape or even OpenOffice Draw.