1. No Blog Writes Itself - Behind every blog post you read on someone else's blog is a person just like you doing the writing, editing, and publishing. They have other stuff to do, but they find time to blog.
It won't be different for you. You will never wake up to find out that your blog has done the work for you while you were sleeping. The Keebler elves make cookies, not blog posts. Expect to work hard.
2. Blog Posts Are Not Like Kids - You might love all your kids the same, but you won't be able to say the same thing about your blog posts. Some posts will be home runs that take hours of writing. Others will be opposite field singles that you bang out in 10 minutes as you're headed out the door.
Would this happen in a perfect world? I guess not. Ideally you want each blog post to be as good as the last one, but that's not reality. If your readers expect 4 posts a week, I'm of the opinion that it's better to give them two homers, a double, and a single than to give them just two homers. If you start only posting your best work, eventually you'll stop posting altogether.
3. Consistency is #1 - Building off that last point, the most important thing you can do as a beginning blogger is be consistent. It will help you develop good habits and it will develop a bond between you and your new readers.
The FIRST thing I look for when I visit a blog is the dates of the last few posts. If they seem too spaced out and erratic I'm already gone. If you want me to be a consistent reader you need to be a consistent blogger.
4. Don't Fear the Crickets - Don't be afraid to post something because you think no one will respond. So you only have 20 readers? Who cares, go ahead and ask them a question at the end of your post. I promise you, no one is going to come to your blog, see that no one responded to your question, and laugh at you.
If you never ask for comments because you are afraid people will see that no one is reading, then guess what, you won't get many comments. The worst that could happen is that no one leaves a comment. Really, it ain't that bad. Even the best bloggers get disappointed from low response numbers all the time. Get used to it so you can brush it off and keep writing.
5. Your Most Important Reader is You - I'll read a blog on just about anything if I know the writer is passionate about the subject. If you're writing about stuff that you know well, but bores you, then guess who else is going to be bored? Answer: everyone.
The only chance you have to write an interesting blog is to write something that interests you.
6. You are Whispering at a Rock Concert - Don't expect to be heard right away, no matter how many important people you know or how many links you get. There are so many voices out there blogging about so many different things, it's almost impossible to be heard.
Discouraged? Don't be. Just because it's tough to be heard doesn't mean you don't have something to say. Your voice is unique, so stay true to it and trust that everyday more and more people will find it and stick around if it resonates with them.
7. It's Your Gig - The best thing about being a blogger is that it's your creation. You decide how often to post, what to post about, and every other detail that goes into making a blog unique. Have fun with it, invest yourself in it, and if it's not working out for you don't be afraid to shut it down.
A blog shouldn't be a burden you carry around all the time. If 90% of your thoughts about your blog are "man, i really need to post something", then take a break from it and see if you want to start back up or not.
Blogging isn't for everyone, but for some it will be an amazing experience. You might discover that you don't love writing as much as you thought you did. Or who knows, you might discover a voice you never knew you had and an audience excited to hear what you have to say.
Truth be told, there's only one way to find out, so get your butt in a seat and start creating.