You can find blogs by searching the internet using any search engine you desire or by searching Blogger’s directories, using the keywords that are related to the specific blog post or site that you want to promote.
Most blogs have a capacity for leaving comments. These can be on specific blog posts or pages.
Each form varies, but they usually allow you to post a comment, inside which you can leave a hyperlink to your site.
Others will allow you to mention a specific URL when you post your comment.
These are better because it means that when someone clicks on your username it automatically takes them to your page/site.
In order to choose a good blog to comment on, you need to be careful in your selection.
Check the blog to make sure the content reflects your interests and your style, then check how old the blog is, how often it is updated and if possible, how many views it is getting.
The higher quality the blog, the more the backlink is worth.
When writing blog comments it is important to remember some basic rules about comments:
1. Make sure the article/post is relevant to your page.
2. Address the comment towards the content of that page
3. Offer a genuine opinion.
4. Do copy and paste common comments.
5. Use clear English.
These are important because if you do not follow them, chances are webmasters and blog owners will delete your comments.
Believe me, if I think a comment is spam then I will delete it.