Sculptris is a modeling program, that can be download from Pixologic website: pixologic.com/sculptris/ to introduce for using the similar and more advance program like ZBrush which can be found at the home webpage of Pixologic: pixologic.com
For the beginner there are some points to remember to use Sculptris
Try to make wider wireframe
Please notice that the size or the wireframe can slow the performance of the PC with not big memory. Please make sure you don't make narrow size of the wireframe. Make it simple with wider space
White wireframe on the surface of the modeling. Make sure it has more space.
You can reduce the wireframe density by using the reduce brush.
Make smaller size of modeling
Use the scale tool to reduce the size of the model. Bigger size can reduce your PC performance.
Modeling example using Sculprtis