Crete is a mountainous island with an elongated shape, 260 km long from east to west and between 15 and 60 km wide. The coastline is over 1000 km long and consists of both sandy beaches and rocky shores. The island has several high mountains ranges between which lie semi-mountainous zones which cover the greater part of the island. There are also a few low lying plains as well as a number of high plateaux.
Crete has about 600.000 inhabitants, of which over a third live in the towns of Heraklion, Chania and Rethymnon. The rest of the island is sparsely populated.
Until about 20 years ago agriculture and animal farming (essentially sheep and goats) were the main source of income for most Cretans. Gradually, tourism provided more and more work and has now become the main 'industry' although agriculture (30 millions olive trees, plantations of citrus fruit, vineyards as well as some areas devoted to greenhouse agriculture) remains a big source of income for many people.
Most of the 3 millions yearly visitors to Crete arrive by charter at Heraklion or Chania airport and the majority stay in resorts on the North coast of the island so that it is still very easy to find quiet seaside villages with very low key tourism if you prefer those.
East Crete and especially the area located between Heraklion and Agios Nikolaos boast the highest density of hotels and various other accommodation but at the same time East Crete also has some of the least developed areas in Crete, you just need to get yourself to the South or East coast. And of course, any place away from the sea is still likely to remain pretty unchanged by tourism. You can have the best of both world.
At present Crete has two main airports, Chania and Heraklion. A third one in Sitia (eastern Crete) operates a few domestic flights and the odd charter (2015).
Heraklion airport is the largest and is located about 5 km east of the city of Heraklion. Heraklion airport has far more passenger traffic and flights than Chania airport and is much closer to destinations in the East of the island.
Both airports have a taxi stand and you rarely need to wait for a taxi. It occasionally happens that taxi drivers try to charge more than the normal prices. Easy to avoid as both airports have a list of prices for common destinations displayed at the taxi stand so make sure that you have a look at it before getting into a taxi.
There are also regular city buses from Heraklion airport to the centre of town where you can then catch public buses to other destinations.
The climate of Crete is temperate mediterranean. Winters are mild, with snow on the mountains and rain in the plains but still a good deal of sunshine. The combination of rain and relative warmth make it one of the greenest places in the Mediterranean basin, especially in spring. The summers are hot and dry, particularly on the shores of the Libyan Sea on the south coast of Crete. Crete is a mountainous island and the weather changes can be sudden. It is often windy (anything from a light breeze to gale winds).
There is no "best time" to visit Crete, it depends on what you are looking for. You can see detailed weather descriptions and charts at Crete weather and climate - Best times to visit