How to make standard 2D drawings from AutoCAD 3D solids?

You can either plot your DWG file to the DXB format and read it back with the DXBIN command, or use the SOLVIEW and SOLDRAW commands to create projected 2D representations of your 3D models in given views (top, front, left, axonometry, perspective, etc.). To show hidden lines as dashed, set layer properties on the -HID layers.
For more detailed 2D views/representations of 3D models we recommend a full featured 3D CAD application - Autodesk Inventor or Mechanical Desktop.
Since AutoCAD 2007 you can also use the FLATSHOT command.