Probably the biggest split in pricing and difficulty you'll encounter is whether or not you'll have a webstore (and with it, requisite security or giving a cut to a 3rd party for their platform).
Websites are simple to make, but good websites are a bit more challenging. A website with good content and an underwhelming design is infinitely better for the consumer than a pretty but useless site. Think about exactly what your audience is looking for and put that up prominently.
Your home page should say exactly what you are, why you're the best choice, and how to get in touch without any scrolling, clicking, or fishing. For starters, this means a damn clear logo that matches your storefront (assuming you have one), a phone number at the top in plain text (for phones, no image crap), and a dead-simple example of your best work, possibly with punchline. You don't need an about page since your homepage should be what you're about! The other three things that consumers will be interested in are current sales (homepage), detailed pricing for your services (subpage), and detailed instructions on where you are (subpage which can contain more about the business if desired). Consider a portfolio if it's appropriate for your line of work (satisfied customers, things you've built, etc.).
If you do it yourself, make sure you have a good site before you pay for hosting. This is easy on most computers since you can make a directory, load it in your browser, and see what needs fixing before you actually pay real money for anything. Hosting isn't expensive (I use Dreamhost for $9 a month) and usually includes a .com domain. Manually register your website on all the search engines and link to it within reason elsewhere (add it to your user profiles, for example). Make sure your page titles have your business name and use the most obvious search terms in the content of what you do (seems obvious enough).
If you get a pro service, the more clear you are on what you want, the better. Have it in writing before approaching a designer and work together on expectations. A designer doesn't make content; they frame and present it in the most useful way possible to your consumers. A good designer will guide you on improving your contribution but will expect you to have it ready. Insist on a contract with clear expectations of both parties and deadlines. This is a very mutual thing, since designers have their own issues getting paid all the time. The best things you can bring to the table are pieces of paper (one per webpage) with a mockup of what you want on it done in pencil.
In summary, know what you want, have it written down, and have it ready to go before you either 1) put up your website, or 2) approach a pro.
