How do I start an online IT company?

[Brablo]

I have this idea involving an online database of useful information,
let's say. This website would allow users to perform queries, reports,
with no pop-ups or memory-intensive advertisements (kind of like
Google).

My background is in engineering, and I'm familiar with software
companies - from the sales process as well as the QA (i.e. testing)
process. Programming and other areas are not my forte, but SALES and
MARKETING are.

I know that this idea would cost hundreds of thousands of dollars to
start off. I would need the following:
1. Servers (perhaps)
2. employees (I can probably get buddies to help out with this and/or
find low-cost programmers and other employees in IT)

However, prior to doing all this, I should do this:
1. Have a business plan.
2. Somehow create a demand for this *prior* to implemenation. Another
words, if you provide a service, how do you market it out to get that
initial demand? As a marketer/sales specialist, I know how to sell
products. I don't know how to create demand or awareness about a
brand-new pioneering type of corporation.
3. How do I solicit advertisers?