Click the first logo card located under "Player 1" then choose your starting cards from the chart.
Choose your opponents cards by continuing to choose from the deck of cards in the chart.
A button will appear that says "Get Odds". Click it and your odds will appear in the box.
After flop
To see your odds of winning a hand with specific flop cards simply choose the cards you would like to be displayed as the flopped cards and click "Get Odds" again.
After turn
Pick the turn card and click "Get Odds". This will show you the odds of winning the hand with one card to go.