If you have a TV licence, you can simply check out BBC Parliament coverage live or on iPlayer. The advantage, is than an announcer gives you the name of the MPs as they rise to speak.
If you live outside the UK you may well not get access to BBC Parliament on a subscription package or via iPlayer. You should be able to watch Parliamentlive outside the UK
PRU (Parliamentary Recording Unit) shows a wider range of live Parliamentary debates from the House of Commons and House of Lords as well as committees. The webcasts can be watched on a variety of platforms live, or on demand going back to 4 December 2007. They can also be listened to as audio.
Does watching Parliament online live mean buying a TV licence ? The TV licensing website was as clear as mud. I found a reply to a question about livestreams on Yahoo Answers.
“If you’re watching programmes streamed from a site with no broadcast platform, you don’t need a licence (so long, of course, as this is the only way that you watch TV).
TV Licensing Support
Parliamentlive has Help pages as well as overview videos