Just go to the Game Lounge and go to the bottom of the page (where you can "Find a player whose name starts with:." Just enter "gb001" -- and you can set up matches against the GNU Backgammon software. GNU plays backgammon as well as any human -- so it's great practice. The DailyGammon server allows you to play up to five matches against the bot.
You can see how GNU plays and get a sense for some winning strategy.