First of all, have a look at the map of the constellation Pegasus which is available online over at the SEDs archive. After familiarizing yourself with the Great Square of Pegasus, look at the North-South pair of stars on the western side of the Great Square. Now look at the following map that I prepared
North is at the top and east is to the left. The star 51 Pegasi is located about 1/2 way down the western side of the Great Square and I have circled it in the above image. It is a 5th magnitude star so it ought to be just visible except in an urban environment with lots of light pollution. I will have to leave it up to you to figure out how to find Pegasus at your latitude, time of year and time of night!