Here is an article from Entrepreneur on just that, how to get more visitors and business. Much t of this seems like common sense to me but many potential clients think there is a magic formula for having a successful website.  All I can say is these techniques do work but it takes effort and consistency.  If you do not want to do it yourself it is advised to hire a professional or assistant to do them for you.  As far as I know there is no set it and forget it way to get alot of traffic to your website.

A few things I recommend are:

• Optin for your email newsletter on your website in an easy to find place and sending out your news monthly, bi-monthly or weekly.  
• Search Engine Optimization and creating to the point title and description tags on every page of your website and on page seo.
• An option to sign up for your blog post subscription.
• Posting your blog posts on Facebook, LinkedIn, Twitter and the other social media websites.  In WordPress, the awesome plugin Jetpack automates this process so whenever you post it goes out automatically to these websites.
• Good sales copy and pleasing graphics using the best keywords for your business on each page.

Tips from the article are writing articles for inclusion in other websites so you can get visitors from other websites reading your article.  This is good if you like to write or you can get articles written for you by a copywriter or writing service website.  PPC campaigns are good for websites just starting out as well, since you will most likely be getting little or no traffic right off the bat.

Check out the article from Entrepreneur.  I can help with the implementation of most of these ideas.  Check out my services page for more information.