Sculptris Alpha is the software made for artists who have taken sculpting to the digital level. It has been improved over the years and through many versions, and now you can even make creations there that are compatible with ZBrush.
For beginners at Sculptris Alpha, just imagine that you have a virtual piece of clay and that you can use tools for pinching, twisting, pushing and pulling in order to create a shape that you have imagined. It also offers you the option of painting and making checkered patterns. Plus, you can make mosaics. It is very user friendly, so it is perfect for beginner virtual sculptors.
What you learn with it can also be applied with ZBrush. It is really innovative and you can create in 3D.