Engineering drawing exercises for you to have a go at - they are really good and test and extend your understanding from what you have covered in school
Basic Symbols used in engineering drawings
http://www.wisc-online.com/Objects/ViewObject.aspx?ID=ENG16204
Basic types of lines used
http://www.wisc-online.com/Objects/ViewObject.aspx?ID=ENG16004
Understanding orthographic drawings
http://www.wisc-online.com/Objects/ViewObject.aspx?ID=ENG19304
Updated 2015