//id make this an instance variable, as youd want every player on the same scoreboard to see the teams.
Scoreboard scoreboard = Bukkit.getScoreboardManager().getNewScoreboard();
  //use the dummy criteria
Objective objective = scoreboard.registerNewObjective("Name", "dummy");
  // set the the sidebar, you dont need this if you dotn want to display scores on the right of their screen.
objective.setDisplaySlot(DisplaySlot.SIDEBAR);

  //time to add scores
  //Use the scores to position your entries, makes stuff nicer, you also have a 40 char limit if you go this route
  //otherwise you can use Teams, and use 16 * 3 (prefix, name, suffix) to get a total of 48 chars.
objective.getScore("Team A Kills: 10").setScore(7);
  //This here, will create a blank line. Scores must be unique so i use different chat colors.
objective.getScore(ChatColor.GREEN.toString()).setScore(6);
objective.getScore("Team B Kills: 5").setScore(5);
objective.getScore(ChatColor.BLUE.toString()).setScore(4);
objective.getScore("Team C Kills: 3").setScore(3);
objective.getScore(ChatColor.RED.toString()).setScore(2);
objective.getScore("Team D Kills: 1").setScore(1);

  //Create a team
Team teamA = scoreboard.registerNewTeam("Team_A");
  //here is where we can set the tags, you dont need text an empty chatcolor will work.
teamA.setPrefix(ChatColor.RED + "[Sweg]" + ChatColor.RESET);

  //add the player to the team, make sure to remove upon leave and re-add upon join to eliminate problems with name changes.
teamA.addEntry(player.getName());

//lastly set them to the board.
player.setScoreboard(scoreboard);