There are millions of blogs. Some people are making money and some don't. Most of the bloggers use WordPress at the moment. You need to be certain that your blog is secure.
In my opinion, the best way to make sure your WordPress security is via the use of a secure your wordpress site backup plugin. This is a relatively inexpensive, easy and elegant to use way to make certain your site is available to you in the event of a disaster.
The one I recommend, and the approach, is to use one of the password generation and storage plugins available for your browser. I believe after a trial period, you have to pay for it, although RoboForm is liked by people. I use the free version of Lastpass, and I recommend it for those who use Firefox click reference or Internet Explorer. That will generate secure passwords for you; you then use one his explanation master password to log in.
One step you can take is to delete the default administrator account. This is important because if you don't do it, a user name that they page could try to crack is already known by malicious user.
Make a note of your password! I recommend the paid or free version of the software *Roboform* to remember your passwords.
But realize that security is something that you really need to start thinking about. Do not just be the type, consider action to begin protecting yourself. Do not let Joe the Hacker make your life miserable and turn everything that you've worked so hard in creating come crashing down in a matter of moments.