Keep headers/logos under 125 pixels high. It takes up valuable viewing space, especially for laptop users, that is best left for the good stuff to appear"above the fold" Take a cue from the big companies, simple logos done well say it all. This is our #1 pet peeve - screaming logos and headers!
Let me shoot a scare tactics your way since scare tactics appear to be what compels some people to take secure your wordpress site a bit more seriously, or at the very least start considering the issue.
There are many ways to pull this off, and many involve re-establishing company website databases and more and FTPing files, exporting and copying. Some of these are very complex, so it is imperative that you go for the best one. Then you may want to check into using a plugin for WordPress backups if you're not of the persuasion.
You must create a user, before you can delete the default admin account. To do this go to your WordPress Dashboard and click on User -> Create New User. Enter all the information go to this web-site you need to enter.
Another step to take to make WordPress more secure is to always upgrade WordPress to the latest version. The reason for this is that with every new update there come fixes for security holes making it essential to upgrade early.
These are a few. Great thing is that they don't need much time to do. These are easy solutions, which can be done.