AutoDesk 123D Design
123D Design is a stripped-down 3d modeling and design program. While it doesn't have many of the advanced features of programs like Solidworks or Fusion 360 it is also much easier to use when getting started with simple models.
123D Design is free software provided through the AutoDesk 123D collection, anyone can download and install it for free on their personal computer.
Install Link: http://www.123dapp.com/design
Note: the Autodesk 123D series of programs is being phased out in early 2017. All of the features of 123D Design have been implemented into AutoDesk Fusion 360.
There are a number of tutorials and videos provided at http://www.123dapp.com/howto/design as well as other online resources.