History and Mythology
This is a very old and famous constellation. Having the brightest star in the sky other than our sun, the name canis major originally was the name of this star, Sirius. Canis Major and Canis Minor are the hunting dogs of Orion and whenever mentioned, there is always some reference to the hunter. There is an interesting story with Sirius, which I will mention now. The Egyptians of the Nile would use Sirius as a pointer to the flooding of the Nile. The first day that Sirius could be seen at daybreak was the day of the starting of the flooding of the Nile. Another interesting story is that in the summer, Sirius is in the sky at the same time as the sun, seeing as it is not a summer constellation. This is believed to be why we call hot summer days "dog days", as the Romans thought that Sirius' brightness added to the sun's.
Stars
alpha-Sirius- the Dog Star, this star's name comes from the greek for "scorcher", so-named because it is the brightest star in the night sky Spectral Type-A1 V Magnitude- -1.46 Distance-8.8 ly
beta-Mirzam- this name shows up a lot in Arabic sky charts, and is thought to be related to these star's closeness to another brighter star, in this case Sirius Spectral Type-B1 II-III Magnitude-2 Distance-715 ly
gamma-Muliphen- Spectral Type-B8 II Magnitude-4.1 Distance-1,000 ly
delta-Wezen- Spectral Type-F8 Ia Magnitude-1.9 Distance-3,000 ly
epsilon-Adhara- Spectral Type-B2 II Magnitude-1.5 Distance-490 ly
zeta-Furud-solitary in Arabic Spectral Type-B3 V Magnitude-3 Distance-285 ly
eta-Aludra-this has a similar route in arabic to adhara, meaning virginity Spectral TypeB5 Ia Magnitude-2.4 Distance-2,500 ly
theta- Spectral Type-K4 III Magnitude-4.1 Distance-240 ly
iota- Spectral Type-B3 II Magnitude-4.4 Distance-1,300 ly
kappa- Spectral Type-B2 V Magnitude-4 Distance-650 ly
Star Clusters
There are a few star clusters in Canis Major, but three are the only ones that are worth any mention. M41 is a large open cluster of about 6th-magnitude. It is one of the most spectacular clusters in the sky, a must see with about 50 7th magnitude stars in it. NGC 2354 and 2362 are open clusters, with 2354 being much larger.
Nebulae
Many, but all are extremely faint, not worth too much unless you have a really nice scope
Galaxies
NGC 2207 and 2217 are two 12th magnitude spirals that need a medium telescope to get any details out of.