Where do I have to go to find the eight shards of the triforce?

To find the shards of the Triforce of Courage, you need to find Triforce Charts. I haven't played Wind Waker in a while, so I can only tell you where a few of the Charts are.

Triforce Piece? 1 - Shores/Stones? Of Greatfish Isle [top left piece]
Triforce Chart 1 - Inside Islet of Steel
Triforce Chart 2 - Inside Private/Link's Oasis (need hammer)
Triforce Piece? 3 - Stone Watcher Island [center left piece]
Triforce Chart 3 - Bird's Peak Rock, hit 5-6 switches with seagull (need pe_?)
Triforce Chart 4 - On Ghost Ship (need Ghost Ship Chart to enter), 2 poes and 1 summoner?
Triforce Piece? 5 - Cliff Plateau Isles [top center piece]
Triforce Chart 5 - Pirate (enemy) ship at Needle Rock Isle (looks like a helmet?)
Triforce Piece? 6 - S. Triangle? Isle [lower center piece]
Triforce Chart 6 - Outset Island, Savage Labrinyth, 30 levels down
Triforce Piece? 7 - 7 Star Isles [lower right piece]
Triforce Chart 7 - Stone Watcher Island (under head rock?) (in arena)
Triforce Chart 8 - Inside Outlook Island, in arena (4 Darknuts?) (need Hookshot)

Triforce Piece? - Islet of Steel
Triforce Piece? - Under? Stone Watchers Isle
Triforce Piece? - Outset, under big rock
Ghost Ship Chart - Inside Diamond Steppe Island (need Hookshot)

Sorry if this doesn't answer your question, but I can't read my writing. Also couldn't tell whether I was talking about a Chart or the location of a piece.

Get the letter from Tingle with the incredi-chart and use that to find the triforce charts. Then get tingle to decode them and put their locations on the Incredi-Chart. Then go find the triforce shards.

There are different maps everywhere. Just wait and tingle will send you an IN-credible chart that shows you the locations of the maps, after you've gotten the maps the IN-credible chart will be marked with the locations of the shards, but you need to have tingle translate the Shard Maps and it's like 201 rupees for each map to be deciphered.