The hero characters can be found at the following locations.

Luke: Jedi temple, Mygeeto, Jabba's Palace, Death Star Interior.
Leia: Tantive IV, Theed.
Han: Utapau, Polis Massa, Endor.
Chewie: Kashyyk, Felucia, Yavin.
Vader: Tantive IV, Jedi temple, Dagobah, Theed, Endor.
Emporer: Polis Massa, Theed, Death star interior.
Boba: Kashyyk, Utapau, Mygeeto, Felucia, Yavin, Jabba's Palace.
Yoda: Kashyyk, Tantive IV, Polis Massa, Dagobah.
Obi-Wan: Utapau, Mustafar, Theed.
Mace: Jedi temple, Yavin, Death Star Interior.
Ki-Adi-Mundi: Mygeeto.
Aayla: Felucia, Jabba's Palace.
Anakin: Mustafar.
Grievous: Tantive IV, Utapau, Polis Massa, Dagobah, Mygeeto.
Maul: Jedi Temple, Mustafar, Jabba's Palace.
Dooku: Geonosis.
Jango: Kashyyk, Felucia, Yavin.