No, but if you do talk to someone else using Skype it's free. It's only when you call out into the normal phone network it costs money.

You need some kind of headphones and obviously a microphone (speakers and mic won't work because of feedback issues, they say). A headset is strongly recommended, but that's not much of a problem. The cheapest ones on Amazon are 7 UK pounds, but I've seen ones in the shops here for about 3.