Widgets or Plugins for Wordpress

[MacGuybrush]

I'm going to install a new website wordpress based.
Do you have suggestions for new important plugins for security or good utilities?

Thanks!!

[Verde]

What is the expected theme of your new site?

[MacGuybrush]

'morning Verde, thanks you for your precious help!

I like very much more theme... I like, for example, this:
http://www.wordpressthemesdemo.org/?themedemo=SmartBlue

I need to know which is the most important security plugins, or others utilities..

[Verde]

Buondi, Mac! 
You should install plugin for security:  http://wordpress.org/extend/plugins/wordpress-firewall-2/

I want to advise, never upgrade the CMS automatically. Updated manually only. Updating after 1-2 months after the official announcement new version the WP. First, plugins must be updated to the new version WP.