WordPress on it's own a quite secure #CMS but this doesn't mean there is no room for improvement. A simple but effective way to make your #WordPress installation more secure is to limit the amount of attempts that can be made on your login page. This will block automated or not attempts to gain access to your site by guessing the password.
The #plugin is called Limit Login Attempts. It will log attempts to login, and will limit the amount of times an IP can fail the login process. Over a (custom) limit it will just block any further attempts. Many customizations are offered (see screenshot). You will certainly be surprise by how many attempts are being made by #spambots!
Limit Login Attempts can be found on WordPress.org http://bit.ly/we0JdW