After you open WinSCP you will see a login screen. The hostname will be dragon.math.arizona.edu for faculty/staff or phoenix.math.arizona.edu for graduate students. The port number of 22 is fine, unless you are not on the math network. In that case change the port to 31415
Next you might see a warning like the following:
Finally you get to the transfer file window. You can drag and drop files from your computer (left side) to the server (right side). Files for your webpage should go into your pub_http_internet folder.