I'd start with the manual:
http://manual.b2evolution.net/
Some things are probably out of date, but most of the basics are there. Of course, I may be misunderstanding you, so if you have a specific problem and can't find the info there (or a search of the forums), post more info.

This is the second time of posting and asking for answers to the problem of handling my blogsite. I sensed that the reason why I could not find any answer to my problem was because I put-up many questions at the same time.

So, I will like to know the step-by-step approach to posting new blogs on my blogsite.

Again, if you take a look at the manual, you'll find an intro to using your b2evolution installation. There's a link there that says "how to add content", try that.