I am wondering which is the best way to put spaces in between these 3 images with CSS using Bootstrap 3 RC2 as what I have done at the moment is not auto-resizing the images
As Harm Wellink mentioned, remove your css. You should only need the following html. Notice the "col-xs-4" and the "img-responsive" class. You do not need col-sm-4, col-md-4, col-lg-4 if you intend to have the 3 columns on all screen sizes.