Just make sure your website has great content on it and go on the likes of Facebook/Twitter to get some traffic.
Write tons and tons of content on a niche with decent CPC. You will pick up long tail traffic. Just get to 50 or so visitors a day on one of these sites and $100 a month is no problem.
You can always try building niche sites My partner and I have started building quite a few sites and it's really paying off now. It's also been a great start up for learning how to do more advanced SEO.
Post interesting content,post it in social networking sites such as Face book.It will help in generating traffic.
Promote your site on Twitter and Facebook that will get good traffic. And make sure your content is unique.
There is no easy way to generate that much amount in one month. The only source is publishing quality content.
tips? hard work, for that amount you need a good niche and good traffic. you need a niche that has a lot of content so you can constantly produce 600/1000 word articles and rank long tail keywords naturally which brings earnings up. There is no easy way All the best