1) Find a niche area of interest and build a web site and put AdSense ads on it
2) Promote the website a bit
3) Profit.
The trick is working out what your niche is that hadn't already been done by someone else.
I lucked out with some websites in the UK about fuel consumption (for cars) a few years ago. I invested a weekend of my time and a little promotion effort and it snowballed - initially it made maybe £1 a month for the first year to 24 months but now I get about 150,000 hits a month which with ads earns a decent amount of money (more than you are looking for)
2) Promote the website a bit
3) Profit.
The trick is working out what your niche is that hadn't already been done by someone else.
I lucked out with some websites in the UK about fuel consumption (for cars) a few years ago. I invested a weekend of my time and a little promotion effort and it snowballed - initially it made maybe £1 a month for the first year to 24 months but now I get about 150,000 hits a month which with ads earns a decent amount of money (more than you are looking for)