You may not be a CocaCola or a Starbucks, even a M&S but you have a business and you should have a brand people can associate with.
When those big brand names are mentioned I bet you immediately visualised their products or logo. If you had a coffee shop wouldn't you like to think people started to recognise and visualise your business that easily?
It's not rocket science, though many marketeers would like you to think so. So you've had a logo designed, maybe a business card and other stuff. The trick, no trick really, is to maintain the same look and style with all your communications. That way your 'brand' organically builds on your clients awareness. To do this means you have to be consistent in your approach which includes your website.
The website is quite possibly the most important place to establish your look or brand as it will be one of the first places that your clients will find and see you.
So, quite simply, it is one place you can't afford to cut corners. It needs to be a part of your brand, sticking a logo in the corner does not count. Whoever you use to create your website, get it done professionally and it must be completely in line with your brand.