The clean hacked wordpress site Codex has an outline of what permissions are okay. File and directory permissions can be changed either via an FTP client or within the page from the hosting company.
There are many ways to pull off this, and many of them involve re-establishing much more and databases and FTPing files, exporting and copying. Some of these are very complicated, so it's important that you go for the right one. Then you may want to click here now look into using a plugin for WordPress backups, if you're not of the technical persuasion.
I don't think there is a person out there that after learning how much of a problem WordPress hacking is that it's a fantastic idea. However is that when it comes to securing their sites, bloggers seem to be stuck in this state that is reactive.
Phrases that were whitelists and black based on which field they appear within, in a page request. (unknown/numeric parameters vs. known post bodies, This Site remark bodies, etc.).
Using a plugin for WordPress security only makes great sense. WordPress backups will need to be performed on a regular basis. Don't become a victim because of not being proactive about your this hyperlink site!