Is it easy to earn a lot of money by creating a website?

Everybody and their dog wants to create a website, then sit back and watch the dough come in. It's not going to happen, unless you have something absolutely awesome to provide, whether it's a unique new service or an amazing product.
Ad revenue is usually so low, most people can't cover the basic cost of the website.

Very few websites make "money" (that is, a reasonnable income).
To make money, you need to sell a product or a service. The site must be well designed, not to contain bugs, and follow marketting rules. On average, $3000 is a minimum cost of development.
You will also have to invest heavilly in advertising to have any chance. On average, a minimum of $10k gives a good start. The least investment I have known to "make money" has been $6,000...
People with a "great idea" are extremely rare: I met a couple in 20 years...
So, no, it is NOT easy to make money on the web. In fact, I think it is one of the most difficult way of doing so!
The only ones that are successful are those who use the web as a marketing tool FOR AN EXISTING BUSINESS.
Businesses based ONLY on the web, and earning real income from it are "the big ones", like dating sites, facebok and the like, and who have invested MILLIONS.
One way to find out if you have a chance is to prepare a full business plan, and present it to your banker, asking for a loan. If your banker is prepared to lend you money, THEN your idea is probably good!
... Otherwise, apply for a job at Mc Donald... More secure.

No, its not easy. If it were, then everyone would be rich.

If the income it the point, and you don't really care what the website it about - then the trick is finding the right nitch market, the right product. I knew a guy who realized a certain tool was hard to find. It was made over seas and only a couple of very high priced resellers carried it. He managed to find a wholesaler who would sell them to him at a wholesale price and he now makes a few hundred a month just selling one kind of tool.

The vast majority of websites that you presume are examples of how to make money are not making money and are in fact losing millions. They operate on the basis that they will eventually become profitable and attract long term investors.

If you could create a highly specialised website and attract that specific audience then you could find a buyer for the site. Given the vast amounts of web businesses out there you have to be quite unique to stand out in the crowd.

No, it is NOT easy.

You need to first learn artistic design, then you need to learn how to turn that design into code.

You'll need to learn HTML, CSS, C++, JavaScript and possibly jQuery. You could also add Visual Basic, and PHP, and Ruby, and any of a number of other web-based languages. Learning all this is not easy, and becoming super proficient is even harder.

But if you ever get to the point where you are expert at it, having spent all your money on college, you can make enough money to pay off your college debts in 15 years if you don't spend your money on a new car or a new house or vacations, etc.

And THEN it will be easy to earn a lot of money, except then the industry will have moved forward, and you'll need to learn a whole new set of web-development languages and start all over!

You have to make sure you really love this stuff before you dive into it, because other wise you can end up pulling your hair out in frustration.

But don't let that dissuade you, you go ahead and pursue your dream goals.

Yes you can earn money. It depends on the idea or purpose of the website. Look at facebook it was made to connect with people and now it turned out to be a really expensive company.
I don't really think advertising is necessary that much. If you have an unique idea or purpose the word will spread by itself. You won't need to spread it

Look! there are millions, maybe billions of websites on the web. Not everyone is out there with a motive to earn money, but yeah! a website can fetch you money. Since you already have an idea, so my suggestion would be to continue whatever you've been doing and don't just be totally dependent on the website. Who knows, whether your idea clicks and you might get earning big.....but there's also other side with equal chance that your idea might fail. So, it's more of a gamble.

My take on this is although it is not easy(nothing is).......I wouldn't stop trying. Good Luck

Hahaha It is not easy first you should be a good web developer and seo person if u don't know about seo u will never earn more and more money so seo is the most important part of all E-Business websites/blogs.

For a website that earns lots of money you need to invest lots of money.
Anyone saying you can do it for $5-10k needs to be smacked in the head with a rubber mallet for a reality check. 10k will barely cover ONE good programmer for 2 weeks. ($125/h contractor * 40h/wk * 2wks = 10k)
Realistically you're looking at $1mil minimum to start (design, programming, QA, marketing).

If your website is good and worth visiting the main issue is getting the word out, how to advertise...

Unlike the rest of the answers here I am going to assume you have an amazing idea and the second people stumble upon your website they are going to tell all their friends and they're going to tell all their friends etc. you can't be tempted to over advertise either it'll just make people quit before they start.
(ad revenue can be pretty low depending so you may need money to support growth or ongoing costs)

All going well a website is a never ending job, with maintenance and updating the UI upgrading your host to support more traffic which will all need money and constant monitoring.

If you do think you are ready to start learning then start, You'll need HTML and CSS for basic functionality, if you want users to log in, you'll need PHP or RUBY (there are others but these are what I use), if you want interactive design with animated objects you'll need to learn JavaScript (again there are other ways).

Good luck and remember you don't need to start from scratch at first you can start with a template.
(I learn best when I deconstruct a finished template)