OK so I went into a store today to play a bit more with the Macbook Air, and it seems as though an open window cannot be fully maxmised, the way it does on Windows? It does this weird thing where a window will only get a bit bigger where the info can be seen, but it won't fully maximise?
Annoying, I know. There are a bunch of utilities that fix this. I use this:
https://www.macupdate.com/app/iphone/33166/sizewell
But there are others, search around until you find one you like.
You can also use full screen mode for apps, which IMO works great on smaller screens like MBA.
Another thing I find odd with OS X is that there is no "move" command. You issue a copy command, then when you go paste it, you hold down the option key, and the "paste" command changes to a "move" command. It feels very counterintuitive to me. OS X is full of little quirks like that that feels very weird when coming from Windows.
I'm a big fan of Moom, as it not only can maximize windows, but can also do a lot of other automatic window resizing. My favorite is the Win7 way of snapping 2 windows side by side, it's really useful for finder operations.