Code from meta box tutorial: http://themefoundation.com/wordpress-meta-boxes-guide/ (does not include javascritp files).

example-metaboxes

/**
 * Adds a meta box to the post editing screen
 */
function example_custom_meta() {
    add_meta_box( 'example_meta', 'Example Title', 'example_meta_callback', 'post' );
} // end example_custom_meta()
add_action( 'add_meta_boxes', 'example_custom_meta' );


/**
 * Outputs the content of the metabox
 */
function example_meta_callback( $post ) {
    wp_nonce_field( basename( __FILE__ ), 'example_nonce' );

    // TODO: This should be set to '' if get_post_meta( $post->ID ); is empty.
    $example_stored_meta = get_post_meta( $post->ID );
    ?>
 
    <p>
        <label for="meta-text" class="example-row-title">Example Text Input</label>
        <input type="text" name="meta-text" id="meta-text" value="<?php echo $example_stored_meta['meta-text'][0]; ?>" />
    </p>

    <p>
	    <span class="example-row-title">Example Checkbox Input</span>
	    <div class="example-row-content">
	        <label for="meta-checkbox">
	            <input type="checkbox" name="meta-checkbox" id="meta-checkbox" value="yes" <?php checked( $example_stored_meta['meta-checkbox'][0], 'yes' ); ?> />
	            Checkbox label
	        </label>
	        <label for="meta-checkbox-two">
	            <input type="checkbox" name="meta-checkbox-two" id="meta-checkbox-two" value="yes" <?php checked( $example_stored_meta['meta-checkbox-two'][0], 'yes' ); ?> />
	            Another checkbox
	        </label>
	    </div>
	</p>

	<p>
	    <span class="example-row-title">Example Radio Buttons</span>
	    <div class="example-row-content">
	        <label for="meta-radio-one">
	            <input type="radio" name="meta-radio" id="meta-radio-one" value="radio-one" <?php checked( $example_stored_meta['meta-radio'][0], 'radio-one' ); ?>>
	            Radio Option #1
	        </label>
	        <label for="meta-radio-two">
	            <input type="radio" name="meta-radio" id="meta-radio-two" value="radio-two" <?php checked( $example_stored_meta['meta-radio'][0], 'radio-two' ); ?>>
	            Radio Option #2
	        </label>
	    </div>
	</p>

	<p>
	    <label for="meta-select" class="example-row-title">Example Select Input</label>
	    <select name="meta-select" id="meta-select">
	        <option value="select-one" <?php selected( $example_stored_meta['meta-select'][0], 'select-one' ); ?>>One</option>';
	        <option value="select-two" <?php selected( $example_stored_meta['meta-select'][0], 'select-two' ); ?>>Two</option>';
	    </select>
	</p>

	<p>
	    <label for="meta-textarea" class="example-row-title">Example Textarea Input</label>
	    <textarea name="meta-textarea" id="meta-textarea"><?php echo $example_stored_meta['meta-textarea'][0]; ?></textarea>
	</p>

	<p>
	    <label for="meta-color" class="example-row-title">Color Picker</label>
	    <input name="meta-color" type="text" value="<?php echo $example_stored_meta['meta-color'][0]; ?>" class="meta-color" />
	</p>

	<p>
	    <label for="meta-image" class="example-row-title">Example File Upload</label>
	    <input type="text" name="meta-image" id="meta-image" value="<?php echo $example_stored_meta['meta-image'][0]; ?>" />
	    <input type="button" id="meta-image-button" class="button" value="Choose or Upload an Image" />
	</p>
 
    <?php
} // end example_meta_callback()


/**
 * Saves the custom meta input
 */
function example_meta_save( $post_id ) {
 
    // Checks save status
    $is_autosave = wp_is_post_autosave( $post_id );
    $is_revision = wp_is_post_revision( $post_id );
    $is_valid_nonce = ( isset( $_POST[ 'example_nonce' ] ) && wp_verify_nonce( $_POST[ 'example_nonce' ], basename( __FILE__ ) ) ) ? 'true' : 'false';
 
    // Exits script depending on save status
    if ( $is_autosave || $is_revision || !$is_valid_nonce ) {
        return;
    }
 
    // Checks for input and sanitizes/saves if needed
    if( isset( $_POST[ 'meta-text' ] ) ) {
        update_post_meta( $post_id, 'meta-text', sanitize_text_field( $_POST[ 'meta-text' ] ) );
    }

	// Checks for input and saves
	if( isset( $_POST[ 'meta-checkbox' ] ) ) {
	    update_post_meta( $post_id, 'meta-checkbox', 'yes' );
	} else {
	    update_post_meta( $post_id, 'meta-checkbox', '' );
	}
	 
	// Checks for input and saves
	if( isset( $_POST[ 'meta-checkbox-two' ] ) ) {
	    update_post_meta( $post_id, 'meta-checkbox-two', 'yes' );
	} else {
	    update_post_meta( $post_id, 'meta-checkbox-two', '' );
	}

	// Checks for input and saves if needed
	if( isset( $_POST[ 'meta-radio' ] ) ) {
	    update_post_meta( $post_id, 'meta-radio', $_POST[ 'meta-radio' ] );
	}

	// Checks for input and saves if needed
	if( isset( $_POST[ 'meta-select' ] ) ) {
	    update_post_meta( $post_id, 'meta-select', $_POST[ 'meta-select' ] );
	}

	// Checks for input and saves if needed
	if( isset( $_POST[ 'meta-textarea' ] ) ) {
	    update_post_meta( $post_id, 'meta-textarea', $_POST[ 'meta-textarea' ] );
	}

	// Checks for input and saves if needed
	if( isset( $_POST[ 'meta-color' ] ) ) {
	    update_post_meta( $post_id, 'meta-color', $_POST[ 'meta-color' ] );
	}

	// Checks for input and saves if needed
	if( isset( $_POST[ 'meta-image' ] ) ) {
	    update_post_meta( $post_id, 'meta-image', $_POST[ 'meta-image' ] );
	}

} // end example_meta_save()
add_action( 'save_post', 'example_meta_save' );