In a game laden with spreadsheets, your overview window is truly the One Spreadsheet to Rule Them All. This window is the one of the most important parts of your UI - it tells you what's going on in the area of space immediately around you, and is also your primary method of interacting with the ships and objects in space. While you could in theory fly without it, do so in any real PVP situation and you're going to have a bad time.
There's a lot of information that this window could potentially show you, and depending on the situation that you're in you're likely to have different priorities. Thankfully the overview window is heavily customisable and can be tweaked to only provide the information that you feel is important for the task at hand. This means that those of us who don't feel a strong desire to view every piece of detritus listed individually can remain blissfully unaware of their presence as we cruise through the spacelanes, while those dedicated sightseers who thrive on such information can create themselves a setup to cover all of their dirt-watching needs.
This article will focus mainly on the Why of overview setup more than the How. For a basic walk-through of how to set up your overview for general PVP, I recommend this guide on the Eve University wiki. For similar discussions to this one, you may also want to read my entry on the directional scanner and the rest of my client setup series. Since my background is mainly in small gang and solo PVP, I'd recommend applying some common sense if your typical PVP is on a different scale - I've tried to point out where things might be different for large scale fights, but I'm happy to defer to the experts on that one.
This article will focus mainly on the Why of overview setup more than the How. For a basic walk-through of how to set up your overview for general PVP, I recommend this guide on the Eve University wiki. For similar discussions to this one, you may also want to read my entry on the directional scanner and the rest of my client setup series. Since my background is mainly in small gang and solo PVP, I'd recommend applying some common sense if your typical PVP is on a different scale - I've tried to point out where things might be different for large scale fights, but I'm happy to defer to the experts on that one.