Skype phones for computer to telephone, on the net are very cheap, just search for VOIP phone, they work perfectly with Skype. You should get one for a tenner or less (plus the usual delivery garbage).
For proper Skype work, the free computer to computer with video, I tend to use a headset with a tiny boom mike, purely because I then don't disturb anyone who is watching say the telly by having the speakers on.
The cheapest way for computer to computer is to buy a wecam with a built in mic, and use the speakers on the computer. My last very good resolution cam with a mic built in, of which part I don't use, was about 7 squid.
All this is of no use of course, unless you have the skypename or email address of the person you want to call, you have to use Skype to trace them first, and get them onto your list of contacts.
Bogs (bandit175)