This isn't as straightforward as Istanbul as the capital isn't really a tourist location. There are two metro lines with a proper intersection (no need to pay twice here) and 3.50TL would buy you 2 journeys to travel on it. Just go up to the ticket booth, hand them the money and you'll be handed back a ticket. Drop it into the machine on the barrier to get it validated and to gain entry into the network. I think the ticket is only valid for one day so there's no carry over to the next (at least with the two journeys I'd bought). The metro itself is quick and clean (I didn't see anyone eating or drinking which probably helped there).
Unlike Istanbul I found no problems at all with the taxi service here and I would recommend this for getting to the places that the metro doesn't reach. I'm guessing not many tourists means the scams haven't really taken hold here. An indicative cost was that it cost me 10TL from the Havas bus stop in Ulus to the hotel and 12TL from the Kecioren watefall to the hotel. Both equate to less than £5.
The rather complicated tube map
At the single interchange that the Ankara Metro has. It couldn't be any easier.
"Sonraki" is next and "Son" is last. This helps ensure you're on the right platform.
This is the ticket office. It's similar to the french "billet".
This is the ticket machine, just pop your ticket in to authorise it and open the barrier. Don't forget to collect it on the way through.
Leaving the metro to get the Havas bus to the airport. You'll enter the bus station on an upper level simply walk down and back under the walkway you've just descended from and you'll see the Havas bus waiting outside.
This is the pickup point close to the stadium complex behind the 2 stadiums. If you want to be picked up from here the entrance is to the north of those buildings.