Blog posting is as simple as going to a particular blog and submitting your content. You have look for blogs that interests you at several places on the social media network. If you are interested in Online marketing you could try Sphinn.
Hi Alzbeta, With the same dought in my mind, i had entered into this forum, so that i could have a clear cut picture of blog posting.
You can try to register on wordpress or blogger. These are free blogging sites. You can post about anything that interests you.
There are tons of free blog providing sites are there but blogger and wordpress are the best of all. Its free and get index very fast if you provide fresh content on regular basis but only onetime promotion is needed rest it will be crawled automatically.
Try to search for list of Blog posting sites. But I also recommend that you should try blogger and wordpress...
search for blogs in Google. First learn how other people are commenting there. It is same like posting in forums but little different because, in some cases, you don't need to register. But its fun and sometimes gets too boring. thats blogging.
What is the context for posting. Are you just interested in commetning on blogs or are you trying to build back links to your site? If it's the latter then use http://www.inlineseo.com/dofollowdiver/ Do Follow Diver. It finds sites in your niche that allow do follow comments and will help you build back links to your site
Which one is the best for you also depends on what you want. Do you want to be indexed fast? or is your emphasis more on creating backlinkpower for other projects?