Once you've set up your blog, it's time to start writing articles, or posts, that will draw in people to read. It's best to decide first what you want to talk about, and how to show that information. The best way to do this is to set up a schedule, so you know when to post and can prepare the posts ahead of time.
The first important article you should write after a disclaimer statement is an introduction about yourself and your blog. It should be fairly simple, with who you are and why you're setting up your blog. It should also cover some of the basics—how you got into genealogy, the names you're researching in your genealogy, and other things relevant to the subject of your blog. If you're doing a blog dedicated to a special area, explain why you chose that topic. If you're focusing on a certain family or person, talk about them.
Beyond that initial post, it's really up to you what you post in your blog. Some post articles about their current research or new finds in their family tree, others post about new software or websites they've been using, or new family connections they made. Some even post about projects—how to get their kids or grandkids involved in genealogy, or scrapbooking, or even writing family history. So long as it's relevant to what you're blogging about, it's relevant for a post.
If you're not sure what you want to blog about, try these subjects:
* Your brick walls—brick walls are the parts of your family tree that you have not been able to push further back in that line. Usually this is a person whom you have limited information on. Either the name is incomplete, or the birthdate, and nearly always, you have no information on their parents. Blogging about these might help you get in contact with others who had similar problems, or might even have the same person in their tree, who can help you get past that obstacle.
* Surname intro posts. As stated in the previous article, it helps to have posts dedicated to each of the surnames you are researching, with details on some of the more important members of the family so others with the same surname can find you and get in contact with you.
* Family stories. Posting family stories, particularly how your family migrated from where they originated to America or wherever they currently reside is a great way to get people interested in your family. Especially your own family, since most people only know a small fraction of their own family story.
* Old family photos. A great way to share what your ancestors looked like, and to help get some people identified, if you have photos with unknown subjects in them.
* Timelines, maps, etc. Anything you can think of having to do with your family story is relevant. If you need help for more ideas, Geneabloggers has daily blogging prompts, several for each day of the week. The next article will go more in-depth on the topics that can be found there. These and many more are available to help give you ideas for what to post about your family and genealogy.
Don't feel you need to follow any of the above. The most important thing about a blog is to make it your own, and to get that information out there. Good luck in your blogging!