Have you ever found a blog on a subject that interests you only to find that you fall asleep while trying to read it?
Blogs are not scholarly essays. They are not reports. They are not white papers. They do convey information but if you want avid readers, convey that information in an entertaining, conversational way. Let your readers get to know you by having a conversation with them. Ask questions – also a good way to get comments. Before you start to write, get a mental picture of your reader. Talk TO him, not at him.
Read your post out loud – yes – out loud. If you read it to yourself, your brain will compensate for little errors. Reading out loud allows you to find phrases that make you stumble or hesitate. Notice where your commas are. Is it a natural place to pause? If a comma makes you pause where you shouldn't, remove it. If you find a spot that's confusing, but a comma would make it clear, add one. The absolute rules of grammar and punctuation do not apply here. Readability and 'understandability' are what's important. Write like you talk, not like you write!
A word about spelling – it must be perfect. Don't rely on a spell checker because it won't find misused words like there for their or your for you're and on and on. Reading out loud will help with this too, but to spot those pesky typos, read your copy backwards. That makes you read word for word and those typos should stick out so you can fix them.
SEO is important but give some thought to incorporating your keywords in an engaging way. Your keywords should suggest good sentences. If they do not, do some more keyword research
Make your blog interactive. Interactive? Yes – if your reader has something to do he will be more likely to stay this time AND come back later. Put up a survey or a poll. Make him know that you value his opinion.
Don't forget to ask him to sign up for your feed or newsletter. If you want him to do something, you must tell him what you want him to do.
Pay attention but keep it light. Make your blog sparkle and your readers will take a shine to you!