The last thing you should know is that (for the most part) you aren't stuck with the default window size. By grabbing any of the corners of an application window, you can drag that corner and stretch the window to a size that is more comfortable for you. The same applies to the top, bottom, and sides of a program window.
As you position the cursor on a corner or a side, you'll see the cursor change to a double-headed arrow. Just drag the side or corner to where you want it, and you are done.