I agree that you should read a book or two but it's a lot easier to learn from someone else showing you, sometimes even beginners level books assume that you will have some knowledge of the terminology that anglers use and that can be frustrating. If you google angling tuition there are a number of professional coaches who offer lessons, there's bound to be one near you. Some of the larger commercial fisheries have resident coach, so worth googling commercial fisheries too. Many of them can supply you with tackle for the day, which is worth it if you're not sure about whether you'll like it or not, as the initial set up cost can be quite high. Obviously though, such coaching sessions won't come cheap.
Fishing is the largest participant sport in the UK, well over 3 million anglers, so there's a good chance you already know someone who fishes, a friend, a colleague at work or maybe even just a bloke in your local pub. Get talking to them and there's a good chance they'll offer to take you for a session. You'll need an environment agency fishing licence
http://www.environment-agency.gov.uk/homeandleisure/recreation/fishing/31497.aspx (buy a day licence first and if you like it buy a full one), a day ticket at the venue and some bait, plus fuel costs. Oh and pint or two for your "instructor".
One thing to always bear in mind is that to fish you need a licence, and unless your fishing at a free venue (very rare nowadays) a day ticket. You can be fined for fishing without a licence and have your tackle confiscated. No great shakes if all you've got is a hand line, but if you've just forked out a few hundred on tackle is worth the risk for the sake of a few extra quid for the licence?
Give it a try, it is a very rewarding pastime, though sometimes you may lose the will to live when they just aren't biting (been there, done that lol). Then read the books, you'll have a better understanding of what they're describing. It's been a while since I read one so can't really recommend one to you, except perhaps "The Compleat Angler" buy Izaak Walton. It was probably the first serious attempt to describe how to fish and it really is still a valid piece. Remember, old Izaak didn't have carbon fibre rods, high ratio closed faced reels and electronic bite alarms - but he did catch a lot of fish.
Tight lines and wet nets,
Rog.
