Become an affiliate:
This is probably the easiest and the hardest way to make money online. It's easy as it cost's you nothing to join an affiliate program, but it's hard because so many affiliates fails. The stats are 95% of all affiliates never make a cent, but there is help.

Create Your Own Software:
This could probably be a bit over your head if you are just starting, but software is selling like hotcakes online. A few examples would be, Headergenerator.com and Ecovergenerator.com. These basically just allow you to create your own graphics for your website with out having to hire it out to others.

Create Your Own Ebooks:
This is the easiest to get up from the ground as you don't need a lot of expensive resources or knowledge. While it seems every man and his dog are creating ebooks and selling them online, it's still a very viable business, and very profitable if you can come up with a topic for your book that is in great demand.

Create A Members Site:
This is becoming the most popular method of making money online now. Membersites that pay you monthly is where the money is at. Why work your butt off to write a book that's only going to pay you once, when you can write content that will pay you month after month.

Sell On Ebay:
It can not be seen that selling on Ebay ever fading to the point where it's unprofitable to do so. While it may seem everyman and his dog are selling on Ebay, and it's true, it's still very profitable. All you have to do is find a target niche market and give them everything they need. Don't even think about trying to sell electronic goods on Ebay unless you can get them at super cheap prices and have a large quantity to sell constantly.

The best way to learn about Ebay is to get a few products together and sell them. There are plenty of guides on selling on Ebay, most of them you can get from Ebay itself.