The payout structure of a poker tournament can vary from conservative (where many of the players receive some kind of payout) to top-heavy (where most of the money goes to a few of the players). Most poker players prefer top-heavy payout structures because they can win a larger amount. If you are playing a game with inexperienced players it might be better to have a more flat payout structure to reward marginal players - if most players keep losing then they may stop playing to your games.
Whether or not the tournament has a flat or steep payout structure, the winner of the tournament will typically get about double of the 2nd place finisher.
Most single-table tournaments have standard payout structures. For a full single-table tourney (8-10 people), the most common payout structure is to pay the top 3 players with 50% / 30% / 20%. For a short-handed (6 people) tourney, the most common payout is 60% / 40% to the top 2 people. You can check out my home poker game spreadsheet if you want a tournament payout calculator to see how much each player will get paid.
Here are two sample payout structures for a single and multi-table tournament.
HPG ADMIN on March 1, 2013