These are just the basics of how to make money online. Think of it like a college 101 course. I'll walk you through the broad stroaks and ideas of the field, so you can get a general understanding of how people make money online, but don't expect to get a full understanding from reading just this page.
You'll need to click through to some of the other pages listed here, which will give you a more in-depth understanding of the different methods.
Work from home jobs - If you've learned how to make money online with telecommuting you might try a full work from home job or independent contracting. These are similar to telecommuting, in the sense that you work for someone else and are an employee of their company. Work from home jobs, unlike telecommuting, are done entirely from home. Chances are good that you may never meet your employer in person, and they may even be located in a different state, country or hemisphere than you are. These may or may not be done entierely online.
Independent contracting - This is like a work from home job, however instead of being an employee for one company, you sell your expertiese to different companies (or even just one company) as opposed to being on one company's payroll. If you have a skill that can be transmitted electronically, independent contracting over the internet can be a good way to start an online business.
Sell on Ebay (or another 3rd party site) - Whether you're selling your stuff on Ebay, Half.com, Amazon.com or Craigslist, all these sites allow you to make money by using their website, systems, visitors and clients (frequently for a share of the profit) to sell your products or services online.
Create your own website for your off-line business - If you already have a brick-and-moartar business selling your goods or services, adding a website can expand your clientelle and reach. Learning how to make money online with this method will require new methods of advertising, but can potentially grow your business exponentially.
Open your own online store - You want to sell widgets? Great! Forget about the cost and stress of having a brick-and-mortar store and just learn how to make money online by running your entire store out of your garrage. No one needs to know that you change your laundry when you go out to pack their box of goods. Just keep it clean and you'll be good. Your online presence, however, needs to be as clean and plesant to shop on as a high-end boutique.
Make money from your blog - If you have something interesting to say, be it celebrity gossip or model ship building, chances are there's a blogging community out there. Here's the key though, don't just write willy-nilly, write to meet the needs of that community. Once you can do that, your traffic, advertisers and income will grow naturally.
Adsense - Are you knowledgeable about something? Passionate about something? Create a website about it and bring in traffic. Once you've got some healthy traffic going on, add the Google Adsense code to your site and Google will pay you every time someone clicks on an ad. The key to making this work is to generate large sums of unique, original traffic. Repeat traffic (like on a blog) doesn't tend to click ads as frequently. Also, there's usually a less than 1% click-through rate, so you'll need to be getting more than 100 visitors a day to average a click through per day. Of course, this will varry depending on your niche, but traffic will always remain key.
Affiliate programs - This works like Adsense, but it's a little more involved. Make sure to read the entire Affiliate Program guide. So you've got a website that is getting a steady amount of traffic about a specific subject. Most merchants who sell to these niches will have affiliate programs that will allow you to partner with them to promote your products. You encourage your visitors to buy and get a percentage of every sale.
eBooks - If you've ever thought of writing a book, ebooks are a great way to start. Put together a PDF document about some topic you know a lot about. Sell this for $5-$150 per person, depending on what it's about. After payment, customers are given a link to download the PDF securely. You get the money with very little overhead. Of course, you've got to figure out how to get people to buy the book, but with a high-quality product that meets a specific need, it's very dooable.
Email marketing - If you want to learn how to make money online like the big businesses do, you need to learn how to do email marketing and how to do it well. Use your website, blog, ebook sales page, Ebay sales or walk-in clients to generate an opt-in email newsletter list. Periodically (from once a month to once a week, depending on your clientelle) use a service such as Constant Contact to send your entire email list a newsletter. In this newsletter, offer special products and deals (ebooks, affiliat programs, other products) that your readers can buy. If you can generate an email list, no website is necessary (although it helps GREATLY).
Online surveys - There's a rumor out there that you can make good money taking online surveys. Well, yes and no. You can make good money if you can get OTHER PEOPLE to take these surveys and frequently the first step to this is to take the survey yourself. However, if you don't have a resource for other people who are willing to follow up and take the survey as well, you'll never make more than a few bucks per survey.