Meta boxes are basically custom fields which, you could use to add additional data to your content. Custom Field Suite is a wonderful free plugin which, makes it dead simple for you to create custom meta boxes visually for you posts, pages or any custom post types.
It is a wonderful free plugin and have great documentation for you to get start. You can easily create text, text area, wysiwyg, color, select, file upload, user, relationship and loops using visual UI and with minimal code you could display the values in your theme.
The placement rules help you to define, in which scenarios you want to display the custom meta boxes in each content type. You can choose from post type, user roles, exact post or taxonomy terms.
The plugin also have an export and import feature, so it is easy for developers to move from development box to actual server.
URL : http://wordpress.org/extend/plugins/custom-field-suite/
Home : http://uproot.us
Documentation : http://uproot.us/custom-field-suite/documentation/