You probably want
this board.
In answer to your question, Sir Forexample would deal exactly the same damage to himself as the intended target of his attack. In this case, 2d6 base damage, +1d6 fire damage, +3 from his Strength bonus, +2 from Power Attack, for a total of 3d6+5 damage. Although you probably want to roll the fire damage separately from the weapon damage, in case of resistance, damage reduction, etc., that's just a matter of notation.
EDIT:
If there are any choices he's allowed to make
after striking his target, he needn't choose to do so. For instance, a wielder of a brutal surge weapon (see Magic Item Compendium, page 30) wouldn't need to activate its ability, even if he'd said that he planned to before making the attack. On the other hand, if Sir Forexample had poisoned his weapon, he would be subjected to the poison in addition to the attack's normal effects.
