If you are a pro blogger then you must aware of guest blogging and its advantages, but if you are a newbie then this post will help you a lot to understand this term. Guest blogging is nothing but writing an article for a blog which you don't own. For this you have to look for the blogs which accepts the guest post.
In my opinion the guest blogging is one of the best techniques of improving SEO of your own blog. You should devote time for posting on other blog also. This will be beneficial for your blog and as well as for the blog you are writing for. Writing post for higher PR blogs will surely increase PR of your blog by having a do follow backlink from higher PR which is better than posting a link as comment on their post.