Knossos- Largest palace, had complex maze of chambers known as the Labyrinth.
Phaistos- 2nd largest palace, phaistos disc was found here, had a monumental stairway and lustral basins.
Malia- had large stone lined pits, significant in local storage of grain and oil, domestic quarters and a ceremonial area.
Zakros- Had circular pool fed by an underground spring, evidence of a metal industry with smelting furnaces, important port and trading centre.
Agia Triahda- May be a villa complex, not a palace, Knossos style frescoes and harvesters vase were found here.
Gournia- Fishing and trade, along with Zakros was an important industrial and administrative centre.
Pretty limited description, so sucked in. Hope it helps though...
Good luck