Mac: There a few tools out there that simplify windows management on Mac, but Gridsutra's one of the easier ones to use because it lets you organise with keyboard shortcuts or a few clicks of the mouse.
When you load up the Gridsutra launcher, you'll see all your open windows. Select the ones you want to organise, then Gridsutra shows you the various layouts available to you. When you're happy with your choice, Gridsutra organises each window accordingly. If you struggle with window management, Gridsutra's worth a look. You can check out the trial for 30 days for free.