Magento 1.9 – How to Display Products on Home Page from a Category

Create a local.xml under app/design/frontend/yourpackage/yourtemplate/layout/local.xml code of this file are

< ?xml version="1.0"?>
<layout version="0.1.0">
 <cms_index_index>

       <reference name="content">
            <block type="core/template" name="my_default_home_page" template="cms/home.phtml"/>
        </reference>
    </cms_index_index>

</layout>

and create home.phtml under app/design/frontend/yourpackage/yourtemplate/template/cms and code is this file below

here the code

$catgorcollection=Mage:getModel('catalog/category')->getCollection();
foreach($catgorcollection as $category ){

$todayStartOfDayDate  = Mage::app()->getLocale()->date()
            ->setTime('00:00:00')
            ->toString(Varien_Date::DATETIME_INTERNAL_FORMAT);

        $todayEndOfDayDate  = Mage::app()->getLocale()->date()
            ->setTime('23:59:59')
            ->toString(Varien_Date::DATETIME_INTERNAL_FORMAT);

        $collection = Mage::getResourceModel('catalog/product_collection'); 
        $collection->setVisibility(Mage::getSingleton('catalog/product_visibility')->getVisibleInCatalogIds());
    $collection
            ->addMinimalPrice()
            ->addFinalPrice()
            ->addTaxPercents()
            ->addAttributeToSelect(Mage::getSingleton('catalog/config')->getProductAttributes())
            ->addUrlRewrite();
$collection = $this->_addProductAttributesAndPrices($collection)
            ->addStoreFilter()
            ->addAttributeToFilter('news_from_date', array('or'=> array(
                0 => array('date' => true, 'to' => $todayEndOfDayDate),
                1 => array('is' => new Zend_Db_Expr('null')))
            ), 'left')
            ->addAttributeToFilter('news_to_date', array('or'=> array(
                0 => array('date' => true, 'from' => $todayStartOfDayDate),
                1 => array('is' => new Zend_Db_Expr('null')))
            ), 'left')
            ->addAttributeToFilter(
                array(
                    array('attribute' => 'news_from_date', 'is'=>new Zend_Db_Expr('not null')),
                    array('attribute' => 'news_to_date', 'is'=>new Zend_Db_Expr('not null'))
                    )
              )
            ->addAttributeToSort('news_from_date', 'desc')
            ->setPageSize(7)
            ->setCurPage(1);

$collection->addCategoryFilter($category);
}

Block shortcode should have an option to specify products count. Usually it is product_count

Try to update code to

{{block type="catalog/product_list" column_count="4" category_id="3" product_count="12" template="catalog/product/list-officestationery.phtml"}}

Please note that chosen category should contain enough products.