Hi,
Things are in a bit of flux at the moment as regards the recording technology. Tape is the oldest and most cost effective storage but a pain to edit with.
DVD disc recorders have been around a while but are prone to errors, see how many people post on just this site unable to finalise or playback their disc. Best avoid.
Latest are HDD and memory card recorders, still very new but not heard anything bad about either yet.
You can pretty much ignore analogue formats like VHS and Hi8 as they haven't been in wide use for around 10 years.
If you Google camcorder buyers (buying )guide choose uk only you should get a few rsults such as this. Some are more technical than others.
http://www.kelkoo.co.uk/co_3407-digital-camcor der-guide-digital-camcorder-buyers-guide.html
http://www.trustedreviews.com/camcorders/revie w/2008/05/02/Camcorder-Buyers-Guide-Spring-200 8/p1
http://direct.tesco.com/buyersguide/camcorder. aspx
If you go along to your local library they'll also have magazines such as Which and What Camcorder that will be full of reviews of the latest models as well as past reviews.
Once you've narrowed it down to a few go along to a camera shop and ask to see a few models as sometimes a really good camera on paper is too fiddly to use in practice (buttons too small and you keep getting your hand in shot)