It depends. If the sections on your website cater to each other e.g surround a common theme I would only create separate blogs if you have enough content to fill them up in a quality way. Gaining readers, backlinks and reputation as a site will be much easier if you can focus on one blog.
If the content on your webpage is very diverse I would go for separate blogs. That way its easier for your readers and searchengines to grasp your theme.