1)Blogging depends on how you structure and use your Blog.Your article must be on topic and you should have knowledge about deep linking because it is one of the keys to improve search engine ranking. 2)Your Blog is hosted on a different domain.Then, you are in the best position to improve search engine ranking. 3)Publish post should include a handful of links.link internally and link externally helps in improving the ranking. 4)Categories are very important in Blogs.You could link those keywords to that category page and the meta title and description tag are formatted properly. 5)Blog is a long-term process.So that,update your content regularly and then, more visitors will come to your site and increases the importance of your web page.
Yes, this is great one, you should blog your content on external domains. But you should not be too spammy here, blog about some generic topic related to your niche and use your keywords/links at the appropriate place.
The content is the king above all. However the content should be short not as too big and must be attractive so that the user come to your blog and find proper information clearly.