M15 is very easy to find. I usually look for the great Pegasus square as a starting point at the south-western corner of the square. Then I look for a string of a few bright stars as shown in my map on page 4. The two last stars of this string actually point toward M15. In a telescope, M15 will look small compared to M13 and M22.
Smaller clusters are hard to resolve with smaller telescopes.
Good sky conditions will be beneficial. A magnification of 150x or more will bring out the beauty of this cluster. M15 also has one unique feature over most globular clusters, it contains a planetary nebula within its boundaries. M15 has a diameter of 130 light years and is about 38,000 light years away. M2 is located a little more south than M15.