BleepingComputer.com: Advertising on my website

Ok, so i live and work within the UK. I spend some of my free time messing around with different web deleopment tools. I think most people know that alot of people make a fair amount of money from offering advertisement spots on thier website. Not that i have a website that would attract any where near the amount of people for anyone to want to advertise on it, but say hypertheticaly i did how would this work? i mean would need to declare the website as a business or declare it for tax some how ? as i guess it would be an income? Just always wondered how people go about it?

i know this is not a paticually web devlopment question but i dint really know where to ask it.

thanks

In the US, every state has a website that explains quite clearly how it works, and a few seconds of searching yielded this:
http://www.businesslink.gov.uk/bdotg/actio...param=mkt1_home

thanks! will take a look, looks like a lot to look though till i find what i want