These days, they're mostly trained (or at least should be...) to ask for specific examples of you showing good leadership/teamwork/communication or whatever. That's why they often start with 'tell me about a time when....'
The idea is to give them real, true stories of your exploits - the more recent the better. So you could start an answer with 'a good example from my last job was the time that I.....' They'll follow up (assuming they're any good) by asking what the outcome was and what you specifically did in the story.
So the best prep is to go back over any incidents in your last few years that show you doing stuff that's relevant to the job you're applying for. So if you're applying, for example, to work in a call centre you could tell stories of being really patient with someone who's very upset/angry/dissatisfied etc. Or examples of you handling somebody who doesn't speak good english.
As long as the stories are true...
To ask what you see yourself doing in five years time is a bit meaningless, really. Few people have a planning window that big. And the real answer for most of us is: "in work, please god"
Just play the game - remember your objective is to avoid being rejected. Do that a few times and you'll get offered the job. You may or may not want to accept the offer but the relationship changes the instant they offer you the role - you have the power.
Good luck.
