You can travel to Crete by plane, landing in one of the islands international airports; Heraklio or Chania.
A lot of charter companies have directly flight from all main airports in Europe in the summer time. Outside the season, most of the big travel companies can arrange flights through Athens.

There are also possibilities to travel to Crete: Chania, Rethymno & Heraklio harbour) by ferry from the Greek mainland.