I’m working on a news website. (wordpress.org)
I want to add a quote on the header with an image.
Please have a look at this 
For this I want to add a check box on the post publish section (post.php)
like this 
Please guide me on how to do this, should I use custom field or what?
should i try custom metaboxes… or custom post type ?
I think using CPT may not be necessary as we already have post formats. Trun on “Quote” post format and their you can add the quote, the image as featured image. And on the header section just query for the post format and show the latest one or use jquery if you like to have multiple on a slider.
You can use a post meta box/or excerpt for quote source/author/name, title for the quote preview title.
You may not need to use custom post types … you probably can use the EXCERPT field for the story and then you will need to do some development work to include this Quote with Image in your theme.
A simple approach is to install GLOBAL CONTENT BLOCKS and create the quote and image you want to use. I’ve used this with many digital agencies who want better control over the quote and image.
You can then edit your theme header.php or single.php to include the shortcode … or do something a bit more advanced http://wpxpert.com/category/gcb-advanced-usage/