If you come with your own car or camper to Crete, it is advisable to go by ferry from Italy to Patras or Corfu or Piraeus. From Piraeus then you take the ferry to Heraklion. Most shipping companies offer a round-trip discount by booking in advance.
Whether with your own car or with a rental car, take the highway from Heraklion to Aghii Deka (Agioi Deka, Άγιοι Δέκα) or Mires (Moires, Μοίρες). In Aghii Deka turn left, direction Flathiakes (Φλαθιάκες) and Apesokari (Απεσωκάρι). From there turn left and up to the Asteriousia mountains, pass Miamou and Krotos. Then the mountains down to the coast to Lentas.
Equip yourself with a good road map, which it is best to buy directly in Crete. The newer cards are very good and detailed. Also online map services at your smartphone or tablet are helpful. But do not rely on a navigation device.
At the entrance of Lentas village is one car park and two other car parks at the village square. In high season it is, however, sometimes difficult at all to find any parking in one of the three areas.