Hi pow3r. It absolutely depends on what you want to tell us and what you are interested in. Many topics are quite popular and it is easy to hit one of them or open a new one as well. In my view, it should be something you also like. For example, if you have a job in the it-branch, you could write about how to code or what are the latest components for PCs. If you work at a newspaper, your choice might be the current political situation in your country/state/whatever. Feel free to test out what you like the most or have changing topics in your blog. You are in the America of blogging with steemit as your new grounds.