I've made a living off the net at various points in my life, it's certainly possible but is not nearly as easy as any of the ebooks suggest.
There are two basic ways to make money on the internet:
1) Sell a product or service yourself.
2) Sell advertisements
The bulk of the ebooks will focus on the latter, as it usually takes less startup cost and overhead than the former, but the former is an easier way to make money in many ways. But like offline, the easiest way to make a million is to start with $900,000 and the web is becoming more and more like that. In the early days you could get rick quick without nearly as much competition. These days you should expect to spend more time and money than it used to take or you'll have to get lucky.
As to how to do this, if you are really interested I'll tell you anything you want to know, but it really all starts with picking your niche.
Do you want to put up content, build traffic and sell ads? Do you want to sell a service or a product? This makes a big difference, and so does the niche. If you focus on something like video games and music, you can expect to be paid little more than 50 cents per 1,000 visitors. If you pick a better niche you can get CPM (cost per thousand impressions) rates above $50.
It makes a big difference, able2know is a site that wasn't intended to make a lot of money, and as a general site it makes a lot less with thousands of visitors a day than other sites I operate that get less than 20 visitors a day.
Picking the right niche is a matter of finding a profitable niche that is not as competitive as the others. The most famously profitable niches are going to be saturated, so focus on something small and specific and it's your best bet.
If you want to know more about it, just ask and I'll answer as I have time.