I cringe at it now, but when I look at my first business plan, it was a disaster, and it wasn't (in retrospect) that my internet business failed spectacularly. I hadn't put together a realistic budget, and I'd just assumed that marketing would "happen on its own". I took out a loan, based on a second mortgage without identifying where the revenue potentials were.
I designed my own web site, rather than hiring someone to do it for me. Now, I'd taken a college extension course, and I read a few books about Meta tags, but when I look at my old site, I sigh. It was overly elaborate, it barely used CSS style sheets, and it was more work than was feasible to maintain. This time around, I hired a pro - and they installed a lot of server side tools, like WordPress, to let me focus on running my internet business, not maintaining my web site.
A web designer should not only design your site, they should also be able to take care your domain name registration, all of your hosting needs, and all of your software that you may require to run your business successfully. Keep open lines of communication with your designer so that they can give you all of your desires on your site.
Internet speed is one important aspect of My Internet Business Pre-Launch plan that I think many people do not take into consideration. No one surfing the net will want to wait a long time for your page to load onto their computer. So unless you plan to only target customers with high speed internet access, remember all the glitz and flashiness will not matter much to those who do not have the time to load it.
She also helped me set up my customer feedback forums, and talked to me about font choices and usability. While she disagreed with stuff that Jacob Nielsen recommends (mostly because his sites look ugly and dated), she did point out that my content needed to be the focus of my site, and readability was key.
Before you launch into business ready to make millions, you will want to have a plan for getting customers to your site. You can not exactly make millions without any clients. You may have the best looking web site, with superior products at the absolute best prices, but without customers none of that really matters.
Traffic building is still something of a black art, but I'm focusing on keyword ad buy purchases - and believe it or not, advertising in the Daily Nickel newspapers. Since what I sell is household items, and tips on home organization, it's a natural mix of old style advertising and new. I also make sure that I'm in the Organizer's Circle of blog referrals, which helps a lot on getting on to social networking sites and builds relevance ratings.