How do we calculate the returns from the data? We are thinking we would calculate the Price adjusted and calculate the yearly return as: Yearly Return=[Price Adjusted(t)-Price Adjusted(t-1)]/(Price Adjusted(t-1)

Your formula is correct for no dividends, although I could state it more simply as:
Yearly Return=[Price Adjusted(t)/(Price Adjusted(t-1)] - 1. For total return you would need to include the adjusted dividends, e.g. Yearly Return with Dividends =[Price Adjusted(t)+Dividends Adjusted(t)/(Price Adjusted(t-1)] - 1, Where Dividends Adjusted = DVPSX_F/ADJEX_F