A is for Antedian Assassins.
B is for Benjamin Finney, James Kirk's close friend from his Academy days. They grew so close that Finney named his daughter after Kirk.
C is for Corbomite. It was part of a maneuver.
D is for the Deltived asteroid belt.
E is for Exeter. USS Exeter. After being recovered from Omega IV. It was probably the cleanest ship in Starfleet. But I bet nobody wanted to serve aboard her.
F is for the USS Farragut, where Kirk cut his teeth in deep space and was part of a tragic encounter that haunted him for years.
G is for the Gorn, big green dudes with big guns and very sharp teeth. Strange thing, they seemed a bit lighter on their feet in their earlier, albeit MU incarnation.

H is for the Hermes-class starship. With only one nacelle and light armament, it served as a scout ship.
I is for Ilia of Delta IV, who had to take an Oath of Celibacy before assuming her duties aboard the newly-refitted Enterprise.
J is for Janus VI.
K is for Kira Nerys, first a major and then a colonel in the Bajoran Militia and the second-in-command aboard station Deep Space 9.
L is for Ligon II.
M is for the Martian Colonies, the first manned outposts constructed by Earth humans on the surface of another planet.