Don't be intimidated by web design companies. While it's true that you hire a firm for their taste, experience, and dependability, that doesn't mean that you must hand over your vision and settle for the website they want to give you (as opposed to the one you really want).
It's one thing if you really have no preference about how your website looks and behaves. If technology is not your thing, then you really may end up with a better result if you stay out of the process as much as possible. Just provide some basic content and let the designers roll with it.
But most people do have an opinion about how their business is represented. You may already have a logo or stationery. You may have designed print ads or even TV ads. If that is true, then you are already somewhat experienced at making decisions about how your company is represented visually, symbolically, and contextually.
Decide whether you like the prior representations of your business. You may decide that they worked well or didn't work at all. If the latter is true, then this is a good time to overhaul some of your basic design elements. Obtain an updated logo that you like. Introduce a modern color palette.
Along with great design, make sure that the content you want is featured in the site's architecture. Swap hats with the typical user and approach the website as a novice. What will they hope to see and find?
In the end, you want an attractive website that makes it easy on the user and conveys your message as simply as possible. If you've achieved that, you really will have the website you want.