I've had a university assigment using a pic and had a bit of a trouble to find an easy way to program and simulate for the 16F628A.
So I made this small video tutorial using Mikrobasic, Proteus and MPLAB. You'll need this:
MikroBasic - http://www.mikroe.com/eng/products/view/9/mikrobasic-pro-for-pic/
ISIS - http://www.labcenter.com/download/prodemo_download.cfm