How long does it take to build a website?

For a skilled developer this wouldn't take long at all. You mention that you have very limited HTML/CSS let alone any JS nor backend skills so this may be a bit of a hike. Solution A: Depending on your level of dedication to build and willingness to learn I'd encourage you to continue to expand your front-end knowledge. While there're frameworks like http://getbootstrap.com/ and http://foundation.zurb.com/ you're not required to build templates and components completely from scratch. Everyone has their preference I think http://guides.rubyonrails.org/getting_started.html would be an excellent backend framework to build what you're describing: creating users and allow them to make/reply threads. Scaffolding makes setup a synch. Solution B: The alternative to learning these ascribed languages would simply be to use a CMS like Wordpress and customize to you're hearts content through a user-friendly interface. Conclusion: Regardless of what route you happen to choose, both have their learning curves, though Solution B's isn't nearly as steep. Which will churn out a site the fastest? Solution B. Which will leave you more knowledgable and less dependent? Solution A

Depends on the complexity of the functionality. A basic page can be constructed in minutes, whereas something complex like http://google.com or http://facebook.com can keep thousands of people busy for years. In other words, this question is meaningless.

It well depends on the website. Anytime from a few hours to months and even years, all depending on the website and how many people involved in its design and development.

Good Morning! Well there exists a 'system' that has been, over the last several decades, been optimized to handle 'post/thread/question' style communication. That system is called 'forum'. You might have heard of something like that... :P Jokes aside, a forum seems to be the perfect fit for your goal. I recommend looking at http://www.phpbb.com . It's free and has all the stuff you asked for. The installation will take less than an hour and if any functionality is missing (all the ones you mentioned are guaranteed to be in there already) just look for a plugin that adds it. I hope that helped. Have fun! Best Regards Raszul

I recommend using Drupal 7 to fulfill your needs. It runs off of PHP and MySQL to deliver an unmatched experience in creating websites like the one you have just mentioned. All you would have to do is construct a few content (or node) types, add the custom fields you need (CCK), and adjust workflow (publish immediately,allow comments,etc) and you're set. Obviously building a Drupal theme will be another obstacle for you, but theming inside Drupal is relatively straight forward with a ton of documentation. Drupal can also manage eCommerce solutions with Ubercart. Last Note: Drupal has this thing called Views which allows you to finely tune the display of your content on your website.

I can build a basic website in less than a day's time. E-Commerce websites can take a little longer depending on how much information there is to input. How many products do you have to sell and are those products already listed line by line in some kind of spreadsheet or XML file with prices and descriptions? Uploading one file is much faster than manually inputting every single item.

You can build a basic website in a few hours - even if you have virtually no knowledge. But, a really good interactive website will never end development - what do you imagine Facebook's hundreds of engineers do all day?

Do it in one hour by following these steps.  For beginners who are trying to build an advanced looking website, you will need to: 1) Buy a domain 2) Select a host 3) Install Wordpress to your website (great platform from beginner to advanced) 4) Install a theme 5) Customize/ Add content. Follow this step-by-step video that I made.  You'll have a professional website in no time!

It really depends on what position you are in. If you have enough money to pull it off, then it might be worth it. To create this on your own, you will need to know HTML, CSS, JavaScript, PHP, MySql/and/or/XML. Perhaps more. The point is that if you are in a big hurry to make this idea you have and you have the resources but not enough time and you think that the idea is likely to be successful, then hire someone. Be sure that nothing exists that has already used your idea (I've learned that the hard way more than once). If you have the time, learn programming at the same time. It really opens up what you can do. Since you are new to programming, you will want to hire someone to look over your code and make sure that there aren't things that will make your site vulnerable to data breaches (since it sounds like users will be uploading/creating content on whatever your making). Data breaches are a huge concern. For now, pursue it as a fun project in your free time, when it's done and ready to be launched, hire someone and make sure it serves the user best.