Any good DIY book will tell you how, so will 'how to' leaflets from DIY stores, and you can also try www.diy.co.uk which is B&Q's website. There is also a website www.diyclub.co.uk which may help. It's too difficult to explain without diagrams.
Make a firm and stable base, using hardcore (broken bricks, rubble, etc). Cover with 2 or 3 inches of sharp sand and rake level. Lay the blocks on this, tamping roughly level with the edge of a 3ft long board. Hire a 'vibrating plate' from the hire centre and go over the blocks with this. Finally brush in silver sand, to fill the gaps. It is this fine sand, which hold all the blocks together. Wait for it to stop raining before you start! Maybe next year?