About your problem with drawing walls, read again this:
http://www.sweethome3d.com/userGuide.jsp#drawingWalls
For the connected walls install AdvanceEditing plugin.
For share or insert a picture follow this:
http://www.sweethome3d.com/support/forum/viewthread_thread,1886
You can't upload something directly from your computer but via mediafire.
Dorin