When you are creating a blog there are two main choices – WordPress or BlogSpot. If you want the best rankings you have to go with WordPress. If you aren’t the most ‘computer literate’ person you should stick with BlogSpot as whilst it lacks some great SEO features it is easy as pie to use.
Make sure you host your WordPress blog yourself, otherwise wordpress can delete whenever they want. This also means you can put it on a real domain eg. www.yourbusinessname.com rather than www.yourbusinessname.wordpress.com. The best cheap hosting can be found at http://www.hostgator.com/.