You're dealing with a very large country, by most peoples' standards anyway. There's so much stuff to see and do here that you'll want to get around as much as possible. Travelling in Turkey isn't difficult, it's just a little different from travelling in other places.

Buses: There are an awful lot of buses in Turkey. The most economical way to travel and, if you can sleep on a bus, fairly painless most of the time. The major regional transport hubs are all interconnected with regular day or night services (not always both). Once you reach your desired region it's a question of getting on ever smaller buses until you've made it to wherever you wanted to be. A couple of things that you might not be used to. Currently only 2 of the bus companies in Turkey, Ulusoy and Varan, have the capability to sell you return tickets. You can pay for a return but you'll have to book your seat and time at your destination. It's a good idea to do this as soon as you get wherever you're going as it's all too easy to get stuck. The better, and more expensive, companies will have a fleet of service minibuses at major destinations to collect and deliver passengers to outlying regions. This can save you a fair bit of cash in taxi fares. Try and check it out whenever possible. If you're a woman travelling alone you will not be permitted to sit next to a man, even if you want to. This can lead to a fair bit of juggling around prior to departure if they haven't worked it out already.

The Dolmus is an interesting way to travel. Very cheap and a great way to really get to know people. They always have their destination written on the front and they'll stop for you if there is any way of squeezing you in. Fares are posted, usually above the drivers head, and you pass your money to the front. The change will also come back hand to hand. Can be tricky if you've got a lot of luggage and tend to stop running early evening.

Trains are probably for the enthusiast only. Even the fastest express services take twice as long as the buses and about the only advantage is that you can get slowly drunk at the bar to ease the pain. Theoretically you can book a nice couchette for two on the Ankara-Istanbul train and travel in Pullman style (well kind of) luxury. Let us know if you manage to pull this one off. Berths in 4 or 6 person sleeper carriages are available but we're not talking the Orient Express here. It is nice to arrive at Haydarpasha railway station in Istanbul (built by Germany as part of the push into Asia Minor) on a clear morning and take the ferry across to the European side but you'll probably need a little lie down in the afternoon.

Taxis are going to get a site of their own at some point. It's very simple really. Make sure the meter is working and zeroed before you go anywhere. If that's the case then you'll be fine. There are 2 rates; Day Rate (Gunduz) and Night Rate (Gece). Day rate applies between 7:00 am and Midnight. If you get in a taxi at 6:55 am the guy will drive like crazy to get as far as he can before the rate drops. Similarly if you set off at 11:55 pm expect to crawl along for 5 minutes. The current starting price for day rate in Ankara is 200,000 TL. This varies a little from town to town. If you are getting into a taxi during the night rate period and you're going a reasonable distance you stand a good chance of knocking the fare down to day rate, a simple 'Gunduz lutfen' could halve the cost so try it.
If you phone for a taxi from a restaurant or hotel the driver should not start the meter until you're in the car. If you feel that you're being ripped off make a lot of noise and offer to pay what you feel is fair. On the whole, single women should be fine in a taxi at night. Sit in the back, check the doors open from the inside and if anyone else gets in get out.