A website owner spend lots of money, time, talent to reach to his goal. Sometimes in lack of enough security we can’t go to our destination. Before spending valuable time, talent, and money we should work on advanced securities. Yes there are lots of issues you have to follow for saving your datas. You can follow following tips

1 . Audit Your Security
2 . Generate Custom Secret Keys
3 . Delete Extra Accounts
4 . Use Well Known Tools
5 . Get Better Hosting
6 . Stop PHP Execution in WP-Content
7 . Don’t Look Brand New
8 . Use Strong Passwords
9 . Disable Custom HTML When Possible
10. Remove Unused Plugins andThemes
11. Check File Permissions
12. Report Bugs and Vulnerabilities
13. Configure Automatic Core Updates
14. Change PHP Security Settings
15. Force SSL Usage
16. Block Brute Force Attacks
17. Change Database Prefix
18. Reconsider Security Plugins
19. Your Tip Here!
20. Backup Your WordPress Site

Some usefull links:

Hardening WordPress (WordPress)
FAQ on WordPress security (WordPress)
What to do if your site is hacked (WordPress)
Understand .htaccess and .htpasswd (Apache)
Understand .htaccess and .htpasswd (Javascriptkit.com)
Protecting the wp-admin directory (nicolaskuttler.com)
Cleaning hacked WordPress installation (Blogsblogsblogs.com)