1. Write your website
2. Find a host
3. Upload your files
That's it, that's all you need to know - except how to code HTML, CSS, JavaScript, maybe PHP or ASP, how to edit video (if you use them), how to create and edit images.
Edit: You asked how to create it, not how to find someone to write it for you. Just look on Google for website developer or even look in the yellow pages. They may not be cheap. My current contract I charged $22,000 for - then again I know how to do everything I wrote in my original reply and it's a complicated site. Expect to pay someone who does this professionally to charge anything up to $150 per hour - honestly, I'm not joking. Then again, you can find people who will write a simple site really cheaply - I've written loads where I haven't charged anyone anything at all - which is why I'm not ever going to be rich.
Writing websites isn't particularly hard, and millions of people write their own - which is how I started - but when you're writing for businesses they expect them to attract even more business (which means more money for them) and that's why they hire professionals - like any field, knowledge and experience isn't cheap.
You really can do all of this yourself. There are tutorials all over the internet.
1. Find a HTML Editor - loads of them around and some very good ones for free (Visual Web Developer, SharePoint Designer, NVU, Kompozer)
2. Find a HTML template you like - last time I looked Google listed 200 million of them.
3) Add your content to the template. Unless you're using ASP or PHP you can test the pages easily on your own computer - just open the HTML files with your browser not the editor.
4) Find a host, either a free or paid, it doesn't matter, except most (but not all) free ones will add adverts to your pages.
5) Go through the entire site again, making sure every link works and every image displays properly.
There are tools to help. One of the best free one is Xenu Link Sleuth which produces detailed reports about your site and will check all your links work.
Edit again: honestly, I really would give this a go yourself. Once you're used to it, writing simple HTMLweb pages, with some CSS and maybe some JavaScript, is no harder than writing any other document. It's nice to be able to see something online and say to yourself, "I did that!" You never know, it might turn into a career - I love my job, a hobby I enjoyed turned into a very rewarding career.