This is a small roundup of plugins that add background functionality to any WordPress site and are mostly done for a client at the development stage.

Google XML Sitemaps with qTranslate Support
In a nutshell – A vital element of your SEO arsenal. In order to get good results with the search edginess, you must have sitemap. This plugin does it all for you and works with all search engines.
This an incredibly powerful tool and is so simple to set up but it comes with a vast array of tools and settings. An absolute essential.

Google Analytics for WordPress
In a nutshell – staying with the Google theme for a moment, this plugin allows you to track the traffic to your blog/site and gives you lots of access to lots of extra metadata that you wouldn’t ordinarily get.
Easy to install and a great way of enabling Google Analytics to track exactly what you want to track and gives you more info that you can shake a very large stick at!

Google Analytics Dashboard
In a nutshell – Does what is says on the tin. Enables you easily access all your GA information from the comfort of your WP Dashboard.
Pure simplicity and incredibly simple to set up.

Platinum SEO
In a nutshell – one of many very good SEO plugins out there. This is one of the better ones.
A vast amount of options, and some knowledge of how SEO really works is pretty important, but an excellent tool nonetheless.

Quick Cache
In a nutshell – If you care about the speed of your site, Quick Cache is one of those plugins that you absolutely MUST have installed. Quick Cache takes a real-time snapshot (building a cache ) of every Page, Post, Category, Link, etc. These snapshots are then stored (cached ) intuitively, so they can be referenced later, in order to save all of that processing time that has been slowing your site down.
There are plenty of very powerful cache plugins (W3 Total Cache or WP Super Cache among them) but for pure simplicity and immediate results this is the cream of the crop. Simply install, activate and enable and you’re away. There’s a ton of options, but you can get going with 4 clicks of your mouse.

EZPZ One Click Backup
In a nutshell – once setup, enables you to backup your entire site with one click of your mouse. The backups are stored on your server but can easily be downloaded directly or via FTP to your desktop.
I used to use three different backup plugins until I came across this one. Works every time. A very powerful tool but not so amazing if you’re looking to migrate your site/blog onto a completely new location. But there are plenty of excellent plugins

What ones have I missed out on? Get in touch and let me know.