It never ceases to amaze me how an otherwise intelligent person can so grossly underestimate how much work is involved in creating something.
As an example: a business owner wants a web site with the functionality (and performance) of an amazon.com operational in under a month for less than it would cost to hire a full time web developer for that same time period.
If you're considering having a web site built or building one yourself, here are some key areas you need to plan on and be aware of to ensure your site building process runs as smoothly as possible.
1. Site concept - YOU need to determine a basic concept for your web site including what you want it to do, what needs you want it to fulfill for visitors and what you want it to do for your company. Be as thorough as possible in this determination.
Do you want to generate customers; sell merchandise; establish goodwill with your customers and the public in general; provide sales tools for your sales personell? Decide what you want the site to do and write it down.
Then when you meet with your web design firm they will be able to estimate more accurately the time and cost for building your site as well as give you suggestions on how to achieve your goals. Having this information for them will also help them to see where you want to go with your business. They may then have other ideas that will help you accomplish your aims that they wouldn't have thought of had they not had your information.
2. Design style preferences - take a look at competitive sites and note your likes and dislikes about each.
3. Function preferences - will your site be e-commerce? Have a member area? Allow user sign-up or newsletter subscription? Consider these things BEFORE beginning construction of your site and hiring a design firm.
An important thing to remember is that good designers are RARELY good programmers. When hiring a professional design firm, they usually have both on staff so your sure to receive quality design as well as good programming.
4. Results - Building a website takes time. Building a website that gets the desired results takes even more time. This is an ongoing process that usually requires DAILY work and adjustment to your website as well as continual feedback from your site visitors.
I generally recommend that once the site is built, or during the site building process, that the company hire a full time webmaster who's job it is to administer the website and get visitors to take the desired actions.
Be prepared to make regular changes to your site to get it performing like you want; ALOT of changes.
I could write more about this but I have to run (3 year old approaching). The above should be enough to get you going in the right direction in getting your new website off the ground.