I recently visited Crete Island, Greece. May be I can suggest you some tips to cosider if you are also planning to visit this Island:
1. Weather/Temparature/Clothing - generally its moderately hot (min. temp I heard was 18 deg) & as we visited it was around 28-30 degrees. So no need to take too much wearing for cold etc. half of my ironed clothings remained as it were in the bag :-)
2. Car Rental - If you want to remain in hotel for the whole duration then no need to rent a car - ensure that you get your airport transfer included in the booking. Also generally makes sense to check at hotel (on arrival) if they can provide you a car. For a family small car is enough however if you planning to visit mountain range - take a better vehicle. Check on insurance coverage. Specially important since many providers donot provide insurance for flat tyres in case you drive on improper road (no tar / rough stone roads) so you take care about it.
Also if you want to drive there its good idea to take Navigation - make sure you have Crete, Greece Maps.
Please note that I faced problems with names of cities - I could not find these locations on Navigation. My navigation suggested some alternative names which I had no guess where these places are - But may be this was my TomTom Navigation Problem. Also the names were written in 2-3 different script and it was confusing - in this may be I missed to get informed on the scripts there.
3. Hotel Booking: Crete is wide enough that one cannot make day trip anymore if the other end to be visited. So prior to visit better to find out locations withing 130 km max. (50-60 km/h average = 2 hrs drive one way is ok). So best is to check for the location you would want to visit and search for hotel nearby within 100 km range. In this case it may also make sense to split the stay in 2 different hotels to have better coverage.
By the way - we lived in Bali - and this is very nice location!