It all depends on your budget, time, knowledge, skills and attitudes. You may start with the one that you like and after you succeed in it and gain confidence, you can add another and then other models. The idea is you should find things comfortable and manageable.
We shall briefly dwell on basics of some of these business models which are ideal for beginners. Details are covered separately.
This is the easiest business to start with to make your feet wet. You can sell a product as an affiliate (a.k.a. partner or associate) of a company. You sign up as an affiliate with a company. The company gives you a unique affiliate link ID which you use when you sell online. This link ID is used to track your sales for commission purposes. You earn your commission according to the terms and conditions of the company.
Wondering how do they track your sales? Technology makes it possible. Every computer has an ID for itself known as IP address. The Internet browser you use for surfing (Internet Explorer, Firefox, etc.) saves small pieces of information related to you in your computer everytime you visit a site. These are called 'cookies'. When you visit a website, that website drops a cookie in your computer. When you visit the same site next time, the cookie recognizes your re-visit and sends information to the website. This way your computer 'remembers' your number of visits, user ID and your favorite pages.
Affiliate marketing method is the easiest way to earn online income. Thousands of companies will immediately accept you as an affiliate. You earn commissions on products you sold. The commission procedure is absolutely reliable. However, you should be careful to use the right ID provided to you in the way recommended.
Once you sign up as an affiliate for a particular product, you should learn how to promote your products on-line. Effective free methods are available. If you learn and implement them properly, there is no reason you can fail. Many are earning thousands of dollars. There are paid methods which involve spending on advertisements.
Though affiliate marketing can be done without a website, it is better to have one for better and steady income.
Affiliate marketing is the simplest of all and does not require you to have a website. However, you will need a list of addresses to send your emails. Ready-made mailing lists are available. You must choose them carefully because spamming (sending mails without the receivers' permission) is now a serious offence.
You will need to choose a product to sell. Having a website will generate more profits in the longterm. Choose a product (Read Choosing a products) depending on your interest in the topic. You will not only enjoy working but also gain some more knowledge along the way. Things will be easier.
There are many free resources on the Net to learn about Internet affiliate marketing. For one of the best sites giving away more free reliable information on affiliate marketing and more practical guidance at nominal charges **
Selling your own product
If you have the ability to create an information product you can market it all by yourself or find people (affiliates) to promote your product for a commission. Since it is your own product you get the full profit if you make the sale yourself. When affiliates are promoting your products at their expense and time, you will miss the commission portion but still you stand to gain in terms of your time and efforts. In fact, you are making a sale without doing anything. It is a win-win situation for both the product owner and the affiliate.
You can learn how to create your own product. It is not really very difficult.*
Selling on Ebay
Perhaps this is the easiest method to start with if you like selling physical products online. Ebay is the best place to sell. You can list your ad for free in ebay and after someone places an order you can rush to buy the product and despatch it to the purchaser. Remember you get the payment first. In a way, you can even start off without any money.
However, you should do some research and find out the hot selling products, where they are available at a cheaper price, and so on.
You sign up with ebay and the complete procedure is explained in the website very clearly. Here the trick is to find the right products and a cheaper way to acquire them.
I recommend this source to learn more about ebay marketing tips.*