By A Web Design
In WordPress 3.X.X, it is very simple to update the WordPress core when a new version of WordPress is released. This is a one click process. You need never have to struggle to upgrade your version of WordPress ever. If some of the plugins used need updation, they can be automatically updated as well.
Here are a few optional but good things to do before automatically updating your WordPress core:
There are two methods for updating:
To update your WordPress driven Blog, login to WordPress as administrator, by simply entering the url_of_your_website/wp-admin in your Browser. Enter the appropriate username and password {which was provided while installing Wordpress} and then click on Log In as shown in Diagram 1.

Diagram 1
After logging in as WordPress Admin, a Dashboard page opens as shown in Diagram 2.
All WordPress versions have inbuilt feature for Automatic Update.
From the Dashboard section you can view any Updates provided by WordPress as shown in Diagram 2.
OR
There is also a message displayed at the top of the Dashboard indicating that a new release is available, with new features & functionalities in WordPress core and/or security threats have been fixed as shown in Diagram 2.
If any plugins need updation the total number of such plugins is always indicated adjacent to the Plugins menu item as shown in Diagram 2.

Diagram 2
Click on Please update now to update the version of WordPress as shown in Diagram 3.

Diagram 3
The WordPress Updates page opens as shown in Diagram 4.
This page describes the updates that are available for WordPress driven Blog/website.

Diagram 4
At the top of the page an important message “before updating, please backup your database and files” is displayed as shown in Diagram 5.
There is an updated version of WordPress available, which can be updated automatically or can be downloaded as shown in Diagram 5.
Additionally if applicable, there is a list of all plugins that have newer versions available as shown in Diagram 5.

Diagram 5
Click on Update Automatically to start the process as shown in Diagram 6.

Diagram 6
The process continues automatically. Once WordPress is updated successfully a Go To Dashboard, message is displayed as shown in Diagram 7. Click on Go To Dashboard, to navigate to your WordPress website Admin Dashboard.
NOTE: At this moment of time the WordPress core updation has been successfully completed.

Diagram 7
Verify the new version of the WordPress core as shown in Diagram 8.

Diagram 8
Now, after updating the WordPress core update any plugin used that requires updation as follows:
In the left menu, locate the link Plugins. Click on Plugins as shown in Diagram 9.

Diagram 9
The Plugins page opens as shown in Diagram 10. A list of all plugins is displayed along with the message of newer version available (if any).
In this case, Akismet plugin has a newer version available. Hence, a message is displayed “There is a new version of Akismet available. “as shown in Diagram 10.

Diagram 10
Click on upgrade automatically to start the process as shown in Diagram 11.

Diagram 11
The process continues automatically. Once the Plugin is upgraded successfully a message is displayed as shown in Diagram 12.

Diagram 12
Verify that there are no more updates required via the WordPress dashboard as shown in Diagram 13.

Diagram 13
Updation of the WordPress core and any plugin(s) requiring updation is now complete.