Hi,
I am not far from you, just over the border in Cleveland (in the part that used to be Yorkshire). So I know that you have fairly soft water with low KH - I'll explain more on this later.
What size tank do you have? This is important for choosing fish - they need to be able to fit. All the fish in shops are babies or juveniles and still have a lot fo growing to do.
Rather than books, you are better reading articles on here, and about fish on the website
Seriously Fish, which is written by fish experts, unlike some other sites.
To get you started I should explain that the first thing you need to do is grow some bacteria, which I know sounds a bit odd
Fish excrete ammonia, it is their version of urine. In the wild, this would get washed away but in a tank it just builds up. And ammonia in the water burns the fish's skin and gills. But there are bacteria that live in an aquarium which use this ammonia as food and their waste product is nitrite. This is also poisonous to the fish as it binds to their blood in the same way that carbon monoxide does to us. But another species of bacteria uses nitrite as food and turns it into nitrate. This is much less toxic and we remove it by doing water changes.
There are very very few of these bacteria in our tap water because the water company adds chlorine or chloramine to kill bacteria. So we have to take the few we do have and grow more. This process of growing bacteria is called cycling.
There are two ways to cycle a tank; or to be precise there are two ways of putting ammonia into the tank to feed the bacteria and get them to grow. The first is called fish-in cycling where a few fish are put in the tank and their waste feeds the bacteria. This is the old way of doing things and is now frowned on as it puts these fish at risk of harm or even death. The second is fishless cycling, and we use ammonia from a bottle to grow the bacteria before any fish are put in the tank.
I have two links for you, one for each method of cycling.
Fishless cyclingFish-in cyclingWhichever method you choose you will need a test kit. Liquid reagent ones with test tubes are more accurate than strip testers. A shop may say that they'll test for you but you need to be able to test daily especially if you choose fish-in cycling.
I strongly recommend doing a fishless cycle. Ammonia can be found in some branches of Homebase. My local DIY shop stocks Jeyes Kleen Off Household Ammonia which is a good brand. Failing that you will need to look on Amazon or Ebay.
Fish shops do not stock ammonia as they do not believe in fishless cycling. They will try to sell you a bottled bacteria product instead and probably say that you must get fish at the same time even though all these products say they don't cycle a tank instantly. If you want to try one of these products get Tetra Safe Start as that one contains the right species of nitrite eaters, though even that won't do much if it has been stored incorrectly at any point since manufacture.
I mentioned low KH above. I won't go into details now as this post already contains enough to confuse most people but I will say that with low KH you are in danger of a pH crash during cycling. I know, it happened to me. There is a very simple remedy, so if you decide to do fishless cycling after reading those two links, I'll tell you what to do.
While you are cycling, that is the time to research fish. Visit all your local shops to see what they stock and make a note of those fish that catch your eye. Do not tell them you are doing a fishless cycle!!! Then come home and look up the fish on Seriously Fish. You need fish that like soft water, are suitable for the tank you have and will get on with each other.
I've given you a lot to think about here. Ask any questions you need. The only silly questions are those you don't ask