How to resize windows on OS X
A very good app that I currently use is Spectacle. It is not an official app of the App Store, but it is open source and it does perfectly what you are looking for.
Just download the app, open it and it's done. There are a lot of pre-defined shortcuts for dealing with the window size the way you like, like in this pic:

As you see, if you click on the &quot;glasses&quot; icon, you can see all the shortcuts to minimise, maximise or just change the size of the window.
Of course, these keys are fully customisable. I really like this app.