How to configure the writing settings in WordPress
To configure and manage the system writing settings in WordPress, log into the admin panel and go to Settings menu>Writing sub-menu.
At the top of the page there are two checkboxes related to formatting. The first one is for converting typed smileys into graphical ones; it's marked by default. So, for example, if someone puts :-) in the content of a post or a comment, a corresponding image will be used instead of it on the frontend. The other checkbox is for correcting invalidly nested XHTML code. It's unmarked by default and it should be fine like this.
From the Default Post Category drop-down menu you can select the default category to which new posts are assigned. By default, it's set to the Uncategorized category that comes preconfigured with WordPress. You can put a post into one or more categories when you add/edit that post. If you don't select any category the default one will be used. From the Default Post Format drop-down menu you can select the default format that's used when you add new posts. The formats from which you can select depend on the theme that you use.
As the description on the Writing screen says, Press This is a tool that runs in your web-browser and is used to copy content from other web-pages as posts on your site. To activate the tool either click with the right mouse button on the Press This button and from the menu that appears select the option for bookmarking it, or drag and drop it into the Bookmarks menu of your browser. After that when you highlight with your mouse some text on a web page and you click on Press This in the Bookmarks menu of your browser, a new window will automatically pop out. The window will contain the WordPress form for adding posts and the highlighted text will be automatically included as the content of the post. If you want to, you can make changes and publish it.
From the options in the section Post via e-mail you can configure an email address to be used as a way of publishing posts. Email messages sent to that email address will be published as posts on your site. In the field for Mail Server type the URL address of the POP email server. In case you want to use a mailbox created from you hosting account type the URL of the server hosting your account. If you want to use SSL/TLS encryption, put ssl:// in front of the URL address (e.g. ssl://servername.com). In the Port field put 110 for a plain connection or 995 for one through SSL/TLS. In the Login Name field type the full email address (e.g. firstname.lastname@example.org). In the field for Password type the password of the email address. From the Default Mail Category drop-down menu you can select the category to which posts published via this email are assigned.
Note that in order for emails received at this email address to be downloaded and published on your site you also need to execute with your web-browser the URL address of the wp-mail.php file. It's located in the root WordPress folder on your hosting account. So if the application is installed directly in the public_html directory on your WordPress hosting account, open the URL yourdomain.com/wp-mail.php with your web-browser. This will download the messages that are in the inbox of the email account and add them as posts.
In the text area Update Services on the Writing screen you can list different update services. By default, the URL of the Ping-o-Matic service is listed. When a post is published or updated your WordPress automatically informs this update service which in turn informs different search engines about the updates on your site.
For some more details and screenshots read the tutorial on how to configure and manage the system writing settings in WordPress.