Mac users are well aware of the nuances of Apple's windowing scheme and probably use it like second nature. The problem is that users migration to OS X from Windows may miss some of the windowing shortcuts that they were used to. The traditional red, yellow, and green buttons in the upper left-hand corner of windows in the OS X Finder act pretty much like their equivalents in Windows; however, window dragging leaves a lot to be desired in OS X.
For example, copying a file from one folder to another requires a lot of window gymnastics in OS X. There's a lot of manual window positioning required to place two windows adjacent to each other. Luckily, there are several third-party apps for OS X that streamline window management.
Moom ($10, free trial) is my favorite. It adds a new submenu to the familiar green button in OS X that does more than just zoom the window to its previous size (its current behavior). The Moom submenu (pictured below) allows you to easily move and zoom a window to the top, bottom, left, or right of your screen.
In addition to the five new choices in the Moom submenu, holding the option key changes the choices from half-size windows (which can be too big on a large monitor) to quarter-size windows that are a little more manageable. Moom also includes a cool grid system that allows you to quickly choose the window location by dragging across a small grid. And for switchers, Moom includes the familiar snap-to-edges feature built into Windows.
Other apps in the OS X window management category include Cinch ($7) and Window Magnet ($1). Although it costs more than the others, the additional features in Moom (like the grid and custom window controls that allow you to save window position snapshots) make it worth the extra money for me. Moom's so useful that you'll wonder how you worked without it. It really should be baked into the OS.