One of the best feelings you can get during an Online Poker game is making it to the Final Table of a major tournament. Whether you paid or made it to the end of a Freeroll, you know you are in the money, and in many cases could be in for a considerable prize. You now have a couple of problems:
1) Dealing with quality players (almost by definition the players at the end know how to play Holdem)
2) Ensuring that however large your chipstack is, you make it to a top 3 position.
The second point may seem rather obvious, but it's worth remembering that privilege increments at this point are usually very significant indeed and the difference between 1st and 10th will likely be counted in the thousands.
One problem a lot of players have when they find themselves at the final table that they have no real master plan, but know that being aggressive has been a successful strategy up to this point. If you have not played sections of the tournament aggressively up this point then you are very lucky to have made it this far. Mistake number 1 then is misplaced over-aggression. When you are down to the last 10, the blinds will be huge. This forces players to gamble to stay in contention far more than they would have in the earlier stages. Play aggressively now with weak hole cards and you will find yourself with a 50/50 chance at best.
The next problem at the Final Table is that you will likely see a dominating chipstack. Holdem Poker players often worry about the size of this people lead and feel a need to challenge it. My advice would be do not do so. OK now you have some idea what not to do - how should you play?
The first thing to do is to recognize that the game has entered a final and most dangerous phase. At this stage in the game you will see lots of bluffing, aggression (particularly by the chip leader) and play with less than perfect cards. Assess your position relative to the others on your table. If you are on the short stack then clearly you must take risk. Do not blind yourself away to a point where even if you do win you'll not benefit from doubling up. Go all-in with Ace anything or any pair to have a chance at the double. If you are not short-stacked then sit back, relax and only play premium hands. By premium we are talking 1010 or higher pair and Ace King, Ace Queen. By playing this part of your tournament slowly you'll be able to watch as others put themselves out in all-in confrontations. Obviously if you get a premium hand you have to hope someone will attempt to bluff you, but even if they all fold you'll end up with some sizeable blinds.
If you are the dominant chip leader then being careful not to lose it pick off your opponents one by one, and throw plenty of chips around when medium stacked players try to dip a toe in the water. Always be on guard for high cards on the flop because these will generally be matched, especially so by the all-in short stack.
Monitoring your opponents' position relative to yours (the small stacks that is) should be central to your Texas Holdem Strategy at the Final Table. Once you get down to the final five you should start to take risk, and not before. This way you have little or no chance of being put out of the game in a low paying position - the phrase "you've got to be in it to win it" simply does not apply at the Final Table. Why take a 50/50 chance to double up at 10th place when you can take the same 50/50 in 5th position after half the table have knocked themselves out trying the same thing? At least if you follow this strategy you'll finish 5th if you're unlucky enough not to double.
Realize that it's best to do battle at the end rather than at the beginning of the end (start of the Final Table). Quiet play, even for this short period, will gain you the reputation as a "Rock". Once you get down to say 5th place you'll be running low on chips or even be the short stack because you've been out of the action for a while. Always step back into the game with an all-in playing poor quality hole cards. Other players will fold because you've been quiet for such a long time (or if you have played it has been with Aces, Kings or Queens). After that you're on your own. I firmly believe that anyone playing correct Texas Holdem Strategy at each phase of a tournament will do well and regularly make the final table. You can play to top 5 with skill, progressing beyond that point relationships on luck and circumstance on the day.