"Oh no! I created a site using the 'Publishing Site' template instead of the 'Publishing Site with Workflow" template, and now I realize I do need workflow! Help, what do I do?"
Have you ever found yourself in this position? No worries! This can be easily fixed through the browser.
1. Browse to your Pages Library settings page. (You can get there by clicking on the Site Actions menu --> Site Settings --> Modify Pages Library Settings."
2. Click on the "Versioning Settings" link under "General Settings".
3. Select the "Yes" radio button by the first option on the page: "Require Content Approval for submitted items?"
4. Save your changes.
5. On the Pages Library Settings page, click on the "Workflow settings" link under "Permissions and Management".
6. Create a new workflow using the "Approval" workflow template. Make sure the "Start this workflow to approve publishing a major version of an item" checkbox is checked near the bottom of the page. Click the "Next" button.
7. Configure your Approval workflow as you'd like. Notice at the bottom of the page there's a checkbox that says "After the workflow is completed Update the approval status (use this workflow to control content approval)" and it's checked by default. That checkbox is what ties this workflow to your publishing process. Click the "OK" button to save your changes.
8. Now when you try to edit a Publishing Page in your site, you'll notice you have the "Submit for Approval" button on the toolbar at the top of the page. Approval workflow is now enabled on your site.