The secure your wordpress website Codex has an outline of what permissions are okay. File and directory permissions can be changed through an FTP client or within the administrative page from your hosting company.
There are ways to pull off this, and a lot involve copying and FTPing files, exporting and re-establishing databases and more. Some of them are very complex, so it's important that you go for the right one. Then you may want to check into using a plugin for WordPress backups, if you are not of the technical persuasion.
Recently, the blog of Reuters was murdered by an unknown hacker and posted a news article that was fake. Since Reuters is a news site, their reputation is ruined due to what the hacker did. The same thing may happen to you in the event you don't pay attention.
Note that you should only try this step for new installations. You need to change of the table names inside the database, if you would like to do it for installations.
Oh . And by the way, I was talking about plugins. Make sure it's a secure one, when you get a plugin. Do not install any plugin simply because the owner is saying that plugin can allow you to do that or this. Use hop over to these guys perhaps, or a test site to look at the plugin get a software engineer to examine it carefully. This way isn't a threat for you or your business.