Blogs on Wikia are pages written by one person that can be commented on and organized into a listing, like a typical blog found elsewhere on the internet. They are in the "User" namespace and can only be edited by the user who created it, or an administrator.
Blogs on Wikia wikis
Many wikis have the Blogs feature enabled, and you can find users blogging about all sorts of different things related to the subject of the wiki. Blogs can be used to prompt discussions, express opinions or get answers to questions. Before creating your first blog post on a wiki, it's a good idea to look at what other users are doing with their blogs there. Review the wiki's policies to see if there are any rules or guidelines around how blogs should be used; it's possible that some questions or conversations are better suited for the wiki's forum.
You should always abide by Wikia's community guidelines when interacting with other users—be respectful, helpful and assume good faith. Also remember that, if you're an admin, a user's blog should only be edited by that user. You wouldn't want anyone else making changes to what you wrote on your own blog, after all!
Blogs on Community Central
Since Community Central is a wiki for all Wikia users, your blog on Central provides a unique opportunity to speak to a wide audience. Please be sure to follow the Community Central guidelines when creating a blog post—be respectful and open-minded, and don't post spam or personal attacks.
What should you blog about? It's up to you! Just remember that the readers on Community Central come from lots of different wikis and have a variety of interests. The one thing we all have in common is that we're Wikia contributors! So it's best to focus on topics that will be interesting to that "general" audience. A blog about "Why I love Harry Potter" probably belongs on the Harry Potter wiki, not Community Central. But a blog about "Why the Harry Potter wiki is great" would be welcome, and a great way to promote that wiki to other users.
Also remember that if you have a technical question or need help with something, the Support Forum is the best place to post that. You'll get help from other users much faster there!
When you're ready to publish your blog post, it's a good idea to add a category, so that more users will see it. The blog categories are linked on the Community Blogs navigation menu at the top of the wiki. The category options are: Introductions, Wiki Advice, Opinions, Wiki Promotions and Admin Topics. You should only use the category or categories that actually fit the content of your blog post. Even if you don't add a category, your post will still show on the Recent Posts list.
Wikia Staff Blog
Wikia staff members use their Community Central blogs as a way to talk to the whole community. Staff blog posts are linked on the navigation menu at the top of the wiki, and are also grouped into subject areas: Community News, Tips & Tricks, Founders & Admins, New Features and Contests & Giveaways.
If you're interested in following the details of how Wikia's underlying programming changes from week to week, check out the Technical Updates blog page, updated every Tuesday.