As always, English gets the better of me.

We were playing checkers today for the first time in many years and essentially played it all wrong. Everything was going fine until I crowned my draught. I didn't know what to do next and our game ended abruptly.

The rules say:

When a single piece reaches the crown-head of the board by reason of a move, or as the completion of a "jump", it becomes a king; and that completes the move, or "jump". The piece then must be crowned by the opponent by placing a piece on top of it. If the opponent neglects to do so and makes a play, then any such play shall be put back until the piece that should have been crowned is crowned. "Time" does not start on the player whose piece should have been crowned until the piece is crowned.

Does the opponent use his piece or the players piece to crown the king? Doesn't matter I guess... but if it doesn't matter, why must the opponent do it? Does he skip a turn?

The "king" and gaining the ability to move both forwards and backwards. If a player's piece jumps into the kings row, the move terminates (it cannot jump out (as in a multiple-jump move) until that move has ended and the piece has been crowned).

What does the last line in brackets mean?

A player wins by capturing all of the opposing player's pieces, or by leaving the opposing player with no legal moves.

sigh! this one, i completely understand.

ps: Why are online resources poor when it comes to Checkers rules?