You can perform the following steps to embed a YouTube video to a text and images page, or any content type with a WYSIWYG editor:

1. Login to the Content Editor and navigation to the page you would like to add a video to.
2. Click the "Edit Content" button towards the top right area within the editable region of the page.
3. Within the WYSIWYG editor for the page, click the "Insert / edit embedded media" button on the WYSIWYG editor toolbar which is on the second row towards the right within the toolbar icons. If you do not see this button, make sure the "Show Advanced Options" setting is enable for your WYSIWYG editor.
4. A dialog box will open. Paste the YouTube URL in "File/URL" field. Leave the "Type" as flash and the dimensions should automatically set by themselves.
5. Click Insert.
6. Save your changes.