Web Site first or Business Plan? It almost sounds like: What came first the chicken or the "Egg"?
My recommendation is to work on both at the same time. Although, starting a business plan is the most appropiate way to start, what you need to do is, instead of a business plan.. Set a Goal List: In your goal list define what you want to do, and by when. Everytime you hit your goal, Write down how you accomplished that goal and what you are going to need to get to the next step. You web site will help you See the picture better. Why? because it`s not written on Concrete, you can always go back and modify code, images, and content.
Use both to accomplish your goals.
Once you have a list of your goals and what you did to accomplish those goals, it would be easier to put your business plan together.
One more thing before you begin with your busiess plan: create a simple S.W.O.T analysis... SWOT stands for Strengths, Weaknesses, Opportunities, and Threats...
For example: What are you Strengths? (perhaps a good programmer)
What are your Weaknesses? (shy when talking to customers)
What are your Oppurtunities? (Technology, No competition or something)
What are your Threats? ( 9/11, Economy, Capital, and so forth.)
I use this on a regular basis, to see where the business is at and what I need to do to improve. You can use it to give you a small peep, of what is out there.
Just a suggestion!!
Web Developer / Owner / Consultant
When starting your own business the need to "know-how" is greater than money!