One day we will make Beer from scratch, but in the mean time we will just have to be happy with using kits.
There are many beer kits on the market, we have tried many! But there are 3 that I should mention. the first is Brupacks, they are supposed to be a good quality beer kit, but in our experience they are totally crap! We have used them maybe 4 times in the past 12 years, and just cannot get on with them, the fermentation is unpredictable, and they either taste nasty or turn out to be just too strong.
Now I have got the bad one out of the way, I would recommend Coopers, an Australian company or Black Rock, a New Zealand company. To these kits we add 1kg of golden granulated sugar, often organic. We have made some with white sugar, but the flavour is a lot better with golden sugar. Spray malt can also be used to add depth, make the beer smoother, and gives a better head on the beer. The spray malt costs around £5-£6, but you can get it a lot cheaper online, but then you need to consider postage costs. We have only ever used 500g spray malt and 500g sugar together.
Online suppliers that I have used are Hop & Grape, fast service, but sometimes a little more expensive. And The Home brew shop slower delivery, but sell some of the powders (for wine making e.g. citric acid) by the kg, works out much cheaper.
With any beer, the longer you can allow it to stand, the better it tastes. Ideally leave it 8weeks before opening the first bottle!!