To put it simply, the more you blog, the better. Blogging is the easiest way to grow your site and the easiest way to train Google to re-index your site on a more frequent basis. If you update your site once a year, Google will learn that it only needs to come around once a year to re-index your content, whereas a daily blogger will have Google constantly coming back to index the fresh content. Google rewards dynamic sites that are consistently adding good and relevant content. Keep this in mind if you want to compete for rankings.
So, blog as much as possible. Try to make yourself a schedule or set goals. If blogging everyday seems far too overwhelming, then promise yourself and your business that you will post a new blog once a month and stick to it. Consistent content will build trust with potential clientele as well as give your site an SEO boost. However, be sure not to sacrifice quality for quantity. You need to be writing good and relevant content to build up a reader-base.