Good resource for Pieces of Heart in Twilight Princess?
Solution 1:
There is such a guide built into the game. If you go to the fortune teller in Castle Town and ask for Love advice, you will be shown a picture of an as-yet-unclaimed Piece of Heart.
I believe you can ask multiple times in a row without risk of seeing a duplicate; the teller will go through all remaining pieces and then tell you there are no more. I think.
If you see a picture that you absolutely don't recognize from your play through the game, you've probably missed a grotto or secret cave in Hyrule Field. Ride Epona around all the walls and plateaus in the field and look for entrances.
If you must have descriptions, well, err, go to GameFAQs.