The backgammon rules are pretty straight forward. Each player begins with their 15 pieces set up exactly the way as their opponent. In online backgammon you don’t have to worry about setting up the board as it is done for you.
Every turn the players rolls the dice and moves his pieces as dictated to by them. The idea is to try and bring all your pieces home while trying to prevent the other player by doing the same. To see who goes first both players throw a single die and the one with the higher number takes both of those numbers to form his opening roll. If both dice are the same the players keep rolling until this isn’t the case. After that the players alternate rolling two dice.
Some people play that if both players roll the same number when determining to see who goes first the stakes are automatically doubled.