All online poker rooms have a button you can use to pre-select your action. When the action gets to you, there is no need to click the “fold”, “call”, or “raise” buttons.

You can tell when an opponent is using the autoplay check box. His action comes within split seconds after the player before him.  This is a great online tell. Your opponent made a decision about their hand before waiting to see the actions of the players before him!

When a player selects the “raise any” button, he is signaling he has a strong hand. On the other hand, the use of the “check” button means his hand is probably weak. This does not mean your opponent is using the buttons for these purposes, he could be trying to trick you. Careful observation of his play will reveal when he uses these buttons. 

CardPlayer Magazine has a couple of free calculators players can
use to help improve their game:

Hold ‘Em Calculator
Omaha Hi-Lo

I’m going to let you in on a little secret, that from what I have seen in small and mid sized poker games, not too many players know about this. The majority of players in small and mid-size poker games think that suited cards are a good reason to play a hand.