Photo by Pittendreigh
These two galaxies are about 30 million light years away. They are part of a cluster of galaxies that include NGC 3628. M65 and M66 were discovered by Mechain in 1780. Messier completely missed these galaxies less than 10 years earlier when he was keeping track of a comet that would have appeared to have passed between M65 and M66. It might be possible that the comet's brightness obscured the galaxies from view.
Look for the triangle of Leo and identify Theta in that grouping of stars. Locate Iota on the outside of the triangle. Just as Theta, Beta and Delta form a triangle, so does Iota, Theta and Beta. About half-way between Theta and Iota is an asterism of stars forming what I see as a "cup." Three of those stars will form a nice 90 degree angle. Look at the central star of that angle. M65 and M66 will probably be just in the same field of view as that particular star.
WHAT TO LOOK FOR:
M65 and M66 will appear in the same field of view in most amateur telescopes. M66 is the easiest to find.
M66 is an oval shape and has been compared with the Andromeda Galaxy, M31.
M65 has a bit of a twirl to it, revealing its spiral nature. With good observing, you might be able to see some dark lanes.
Another galaxy in the area is NGC 3628. It is also in the same field of view, but is considerably dimmer. Neither Messier nor Mechain were aware of NGC 3628, but give it a try. Knowing it is there helps find it because you will take the extra time that Messier and Mechain did not take.