Okay, so. Quite a few different factors go into things like habitability, terraformability (Yes I made that word up just now, roll with it) and a planet's (Or satellite's) ability to be colonized.
First is the issue of its size; The Moon isn't very large, only 1/6th the size of earth. (About the size of your mom) Initially this may seem like a major downside, but actually it may have some practical application. Rockets would be much easier to launch, and could possibly house larger payloads as a result. Unfortunately it's small size means it isn't capable of having an atmosphere. But this could also be a benefit in disguise - There would be no pesky molecules in the way of your solar panels.
The moon is also tidally locked to Earth, meaning you could transmit data to Earth satellites 24/7. All in all, the main factor in this is distance. Mars is 200 times further away compared to the moon at its closest, so transit to the moon would be a lot quicker than Mars and you wouldn't have to wait for a orbital window to arrive every two years like with mars. The moon is actually so close, that (assuming perfect data transfer rates) You could be on the moon and connect to someone on earth via the internet and only have a little over 1300 ping. (Which I know at least one of you has attempted to play something at) Comparatively, if we do the same thing with Mars, you would have a ping of well over 187,000. (I doubt anyone here has even had internet connection that bad, unless if you're Australian) That's 3 entire minutes of delay, not exactly feasible for a Skype call.
Tell me what you guys think in the comments!
RE: Could the Moon be more practical to colonise than Mars?