First we need to set up the inventory level of a product at which it will be considered as low stock.

1. Login to admin and navigate to System >> Configuration
2. Scroll down to the Catalog tab and click the Inventory section to open it. Now expand the 'Product Stock Options' section.
3. Set Manage Stock as 'Yes' and add a value for 'Notify for Quantity Below', save the configuration. Note that you do not set 'Notify for Quantity Below' as 0 as it disables the RSS feed.

Lets see how we can display them on the frontend.

1. Using Layout updates

You can add layout updates in local.xml file for a page as shown below:

<reference name="right">
     <block type="cms/block" name="your_block_name" before="-">
         <action method="setBlockId">
             <block_id>your_block_identifier</block_id>
         </action>
     </block>
</reference>

You can enter these layout updates in Magento admin also - Categories, Products, CMS Pages provide a field for "Custom Layout Update".

Let see how we can find the position of a product on the product detail page:

$catId = Mage::registry('current_product')->getCategoryId();
$category = Mage::getModel('catalog/category')->load($catId);
$productPositions = Mage::getResourceModel('catalog/category')->getProductsPosition($category); // This returns all product ids with their position
echo $productPositions[$_product->getId()]; //Print the product postion

Magento is a free as well as a paid software - How? It depends upon which Magento verision you are using - Magento Community Edition (CE) or the Magento Enterprise Edition (EE). But now the question comes - Why will I pay if I can get it for free? The answer is "Great things come for a fee". Actuallay Magneto CE is as good as Magento EE. It all depends on you needs, business size and how much are you ready to invest.