Don't pay to find 'get paid' to sites. Most are easily found with a search engine. Be realistic about how much money you can earn. For example: Most "get paid to read email" sites pay less than a penny or so to read an email. You won't even make minimum wage at that rate. Keep that credit card in your pocket. It might be tempting to accept a "get paid to try" offers and sign up for a service, the problem is that you have to cancel the service within a small window of time. And finally be a little cautious with 'get paid to" sites which try to convince you to establish a down line of recruits with the incentive that you'll earn a percentage of their earnings as well.
Make sure the information in a program or report is up to date. If the ebook you're considering buying is how to sell digital products on Ebay it's a waste of money because Ebay no longer accepts digital products for its auction site. Google AdSense is still a good way to earn money but it's much less lucrative than it was a year or two ago when one click through by a visitor paid several dollars or more.
Understand that people do exaggerate on the Internet and don't clarify their sales pitches. One person sells a course on how to make money by blogging. The individual says they make $7000 per month just by blogging. What the person doesn't tell you is that he/she has over 50 blogs and it took a full year to reach $5000 per month. You might be expecting to make that amount of money with one blog and in a month or two. Another individual shouts that he/she made over $10,000 by sending one email. Just one email. And it's true. What he/she doesn't tell you is that they already had an established list of over 200,000 subscribers that email was sent to.
Rule #1 If it sounds too good to be true, it usually isn't It's a short rule, but works in lots of situations.
You can earn money online but it does take some work and a bit of time. Don't expect to buy a product and turn into an overnight success.