Online poker is very different than live poker. You would not be able to see the opponents in online poker so quite a lot of tell would not be spotted in the opponents. Most people believe that in online poker, there are no opponent tells at all. However, this is not true. There are two main tells in online poker that you should look for:
Time patterns
One of the sources of information is time patterns. However, this is not a very reliable tell on a site like FullTiltPoker. If you are looking for a probable time that it would take for a player to raise, then you might be think that the player is bluffing if he raises too fast. However, it can just be possible that the player might be playing multiple tables or is just taking a short break, answering the phone etc. You cannot really rely on it unless you are absolutely sure that you have spotted a pattern for a particular opponent.
Betting patterns
Betting patterns are actually a lot more reliable since they present facts. There are two things that you need to look for. How much does the player reraise, raise or bet and with what holdings or if they do it consequently. Another thing to look for is the kind of moves that the players make till the showdown.
Handling betting patterns
Raise, bet and check: These are very powerful tells. Most players that have two high cards that are yet un paired, they would bet on the flop. This is a sign of weakness and if you face an opponent who does this, you can raise the turn with almost any hand.
Call, call-check and raise: This is a pattern that is followed by strong UltimateBet players. When anyone check calls and then shows some strength on the turn or river, always fold. The key to follow for putting the opponent on the draw is to evaluate the river, turn and flop. If it is a two suited flop and the opponent check calls, then he would either be on low pair or draw. If the same suit follows at the turn and the opponent raises, put him/her on draw.
All check raises- whenever an opponent checks and raises you, you are beat 90% of the time. Most opponents would not be skilled to check raise as a bluff. Most players would not even think about trying it out. Unless you really have great cards, always fold.
Fast check- this is one of the best tells in online poker. Whenever a player checks instantly, he might have just used the auto check tool that is available in all poker rooms. What this means that the opponent would be planning to check even before you checked or bet. This means that you would get the chance to steal the pot even with a reasonably sized bet. However, there could be a few opponents that might be using this tell against you so you would want to be careful.