After mulling on the idea and getting sure it has legs (that includes a bit of customer development) this is what I would do.
Of course, this is a general idea, particular cases needs to be treated accordingly.

• Wireframing/propotyping your idea

You don’t need technical skills to do this. With the help of dedicated software like Flairbuilder.com, Balsamiq.com, GoMockingbird.com (or others) you can do it quite well and fast.

• Refine your idea based on the wireframe you just made

You can ask your friends, your potential customers what they think and how can be improved. You can even present to investors if you think it’s necessary.

• From this wireframe, make a Minimum Viable Product MVP

Now, you need to decide what to build as an MVP, especially if you don’t have much money to invest and you want to get out on the market.
An MVP will allow you to test your idea in the wilderness, get feedback and also can be shown to investors as a functional proptotype (not just a wireframe).

• Build the MVP

Based on the wireframe you have done and the documentation you can start building your minimum viable product. You can either build it yourself or hire somebody else to do it (or team up as co-founders with somebody technical). This includes also the design of the website.
Don’t think too much about scalability, it’s not needed in this phase (it’s overkill).

• Test more, improve, shout it out

Have a closed beta test of your MVP so you can improve even more.
When you are confident let other people know you are out (press included).
Considering what kind of feedback and how much traction you get you can look for investors, if you think it’s needed.

• Add more features if needed to your MVP, according to your original vision

But pay attention on the users too (some of your original vision may get altered because of that). Be prepared for continuous change.

• Marketing for your website

You can think more about this and marketing doesn’t have to mean “I need money for that”. You can do some things for free (think about viral marketing, ask users to do it, SEO, social media, etc).
Don’t forget about analytics of your site, you always need to know about your users and that will help your marketing efforts as well.

• Reiterate more, be prepared for growth

Hopefully your efforts will pay off and you will see growth. That means you need to be prepared for that (jobwise also), especially for high growth in short time (it can kill you if you don’t manage it properly). In this phase the scalability needs to be paid more attention (from the hardware and software standpoint).

• Build a good business on your website

Think now about your business long term goals and plan accordingly (well, plans can be also changed so be open minded about that). Be patient and execute steadily. Apple and the pyramids weren’t built overnight.
Consideration of an acquisition can come in place but don’t let that be your only way to “make it”.

• Be prepared for change (if necessary)

If your original idea doesn’t work or stales then you need to think about pivoting (overused term, I know), that is, changing the direction (that means some significant changes have to be done on the product too, not just the business model). I hope you will be able to realize in time when it’s time to do it.

• Be prepared to fold

Yes, sometimes it happens that whatever you do with your idea which is now live, it just doesn’t work. As much as you love it, it’s the time to let you baby rest in peace (especially if no one wants to buy it). Sounds like a creepy option but if you know when to fold then you will have energy to start over, with another idea.
Don’t get discouraged if this idea doesn’t work. Max Levchin tried 4 times before hitting big with Paypal.

NOTE: This article was published on Quora.com on April 15, 2012