Creating a Site Column for Page Content
SharePoint 2010’s default publishing content types — Article Page and Welcome Page — usually provide most of the site columns you need for creating publishing pages. The site columns in a page layout’s content types map to the fields that are available for entering content in the page layout.
For example, both the Article Page and Welcome Page content types include the Page Content field. This is usually the main field on the page where users enter their content. What if you want your page layout to display the division of your company associated with each publishing page? You use a site column to add the division field to your page layout.
If you need to make new page content fields to add to your page layout, here's an overview focusing on the publishing content column types:
Navigate to the Site Columns Gallery by choosing Site Actions→Site Settings and then clicking the Site Columns link.
You're in the Site Column Gallery.
Click the Create button at the top of the page to create a new site column.
The New Site Column page appears.
In the Name and Type section, type a name for your site column in the Column Name field and then select your new column type.
The following types are part of the publishing framework:
Full HTML Content with Formatting and Constraints for Publishing: This is the same kind of column type as the out-of-the-box page content control; basically, a general HTML editor where you can add text, images, tables, hyperlinks, styles, and so forth.
Image with Formatting and Constraints for Publishing: A publishing image control that allows for a hyperlink. Because this control is part of the publishing web content structure, you can rely on the versioning and approval process of the page versus a Web Part.
Hyperlink with Formatting and Constraints for Publishing: A publishing control that allows you to select a hyperlink to display in your web page.
Summary Links Data: Summary Links provide more benefits than a Links list or individual links you create because they come with the ability to create groupings and apply several predefined styles. Two Summary Link fields are provided out-of-the-box.
Rich Media Data for Publishing: A container with all the publishing content management benefits for Silverlight content.
Of course, all the other SharePoint column types you know and love, such as Choice fields and Managed Metadata, are fair game for page layouts.
Select a group for your column using the drop-down list in the Group section.
Selecting a predefined group or adding your own makes it easier to locate in the Site Columns library and when you select it for inclusion in a content type.
For the type of content I'm describing, you may want to add it to the Page Layout Columns group or a custom group.
Select or add other properties as applicable.
These may include a description, whether the field is required or unique, and so on.
Click OK to create your site column.
Your site column is created and can be added to content types.
You can use this same process for creating new page fields (information about the page, not content) for your custom layout.