Hi..first of all have a good read through the many pages of the Turkey Travel Planner to get a general overview of Turkey etc..
http://www.turkeytravelplanner.com/If you have the time in your travels minimum 2 or 3 weeks is needed to see the major and some of the minor sites in Turkey..also Turkey is a very big country will vast amount of places to travel to..we need a bit more info from you..are you beach people, into history, cutlture ????? relaxing trip or rushed trip ( however with kids this can be harder )
But we need to know where you might be interested in travelling to ??? then we can better answer your questions.
http://www.turkeytravelplanner.com/itin/index.htmlrenting a car is only needed if you are say travelling along the Western Med coast or for shorter distances...plane and bus travel is excellent in Turkey and recommended for long distance travel.
train service is available..check out more info on Tom's pages
also many things can depend on which month of the year you plan to travel..best months are May or Sept...
http://www.turkeytravelplanner.com/trans/index.html