Believe it or not, a pitfall many bloggers succumb to is trying to write "an essay." Paragraphs and paragraphs of well thought out content will be presented before the readers.
"Why not?" you may ask. "Shouldn't good writing have a solid beginning, middle and end?"
Well, if you were exploring a thesis topic, yes. But this is a blog. On the internet. Your readers are generally going to be people who want light reading that entertains them for a few minutes. They are not a professor you are trying to impress for a good grade.
Most readers only want a few simple paragraphs. They want a single point rather than a fully expressed idea. Ideas can have many facets to them and will, therefore, lead to more content. While it's not taboo to delve into complex ideas, break things up into multiple posts rather than trying to cram it all together in one post.
The length of your blogs will, of course, vary depending on the topic. Just remember to think about how you would react to your blog post if you came across it on the internet.