One thing I'm sure you've noticed about Eve is that space (as in room on your screen, rather than the empty black thing that has stars in it) is at a premium. There are a lot of windows that you'll probably want to have visible, and unless you're fortunate enough to play on a very large monitor you're probably going to struggle to fit it all on.
The default screen layout is, it's fair to say, pretty impractical for PVP. Most people make some basic changes until they find it bearable, others go for a more radical approach and reorganise the whole thing for maximum efficiency. Take a look at a few screenshots and videos of experienced players in PVP, and you'll find a whole range of different layouts built to suit the user's needs.
I'd like to take a moment to talk through the layout I'm currently using, as well as why I chose to set it up this way. Remember that there's no right or wrong here, it's all based on preference.