First let's talk about what a blog is

A blog is web page made up of 'posts' or 'articles' usually aranged in order by date. A blog can be about anything that interests you and ideally should interest other people also.
People can use blogs to post personal news and activities. Businesses can use blogs to post news and business activities.

Blogs became popular in 1997 with the birth of free blogging communities and it has been gaining popularity ever sense. Content management systems (CMS) are the current trend in website technology and usually include blog pages as an option. WordPress is the most intuative, user friendly, seo-friendly, and capable blog CSM software to date.

How a blog can help you

1. It can save you money. Blogging once or twice a week can generate traffic to your website. Google AdWords costs about $1.00-$9.00 every time someone is directed to your website while blogging does this for free.
2. A blog can generate money for you. Whether you have a personal blog or a business blog, there's money in website traffic. Incorporating advertising like Google's AdSense can generate about $.20-$3.00 every time someone clicks on the ad. Google AdSense is free to setup and use on your blog or website.
   If you own a business, a blog can generate leads or online purchases.
3. Google likes websites that are updated regularly.  New content is what brings people online, what encourages advertisers to advertise and how Google makes it's money. If you update you  website/blog regularly(daily or weekly) with 'interesting' content your website page rank 'PR' will increase and more browsers will find your website. Having a higher PR will also make your website seem more credible to web-savvy customers.
4. As your website's traffic and PR increases, your website becomes an asset in itself. There are many people eager to buy such websites if you ever decide you want to 'cash out'.
5. A WordPress blog offers a comment system. A web blog with traffic and type of reader interaction can help your website develop a community as time passes. Reading the responses of your reader's comments can give you insight to the trends and competition relative to your business.