Learn AutoCAD with full-length video courses on SourceCAD, start your 7-day free trial https://thesourcecad.com/courses/
Autocad tutorial showing 3D modelling of USB plug with detailed description of each step. you can get more such practice drawings here http://www.thesourcecad.com
to download block mentioned in drawing go to
http://goo.gl/OUqADQ
source