Make sure you have a private and comfortable place, where you can speak freely, without fear of being overheard or interrupted.
To use Skype with video, you need a webcam. Webcams range in price, and the price does not necessarily reflect the quality. One suggestion is to check a search engine for reviews, or look at listings on Amazon which posts feedback from a large pool of reviewers. Depending on your situation, you may or may not need to purchase a separate headset. If you cannot be overheard during sessions, you may find the quality of the audio through your webcam is adequate and no other equipment is necessary. If there are people who may be within earshot, you should get a USB headset.
A low quality internet connection can interfere with the quality of the audio/video reception. This may result in poor lip synchronization, sound delays, pixilated images and Skype may crash. Skype for chat and or audio alone may be satisfactory in less than optimal circumstances.
Difficulties when Skype is used for audio/video are easily fixed when problems are due to other issues, and the use of teleconferencing has proven a valuable addition to web tools. Those interested in teleconferencing are urged to give it a try, and most will be pleasantly surprised.