The site delivers guidance by default for England, but if you are trading in Scotland or Wales, you should choose your location using the drop-down list at the top of the page. This is because some laws are different, or are differently enforced, in those countries
The guidance is divided up into 15 broad Quick Guides and each one contains a number of more detailed In-depth Guides.
There may be rules you are not aware of, so make sure you explore the site thoroughly.