To manage products, go to Catalog > Manage Products
1. RELATED/UPSELL/CROSSELL PRODUCTS
To add related products for a product, navigate to Catalog > Manage Products > select product to edit, click on Related Products tab
You can do similar as below steps for Cross-sells and Up-sell products
Step 1: Filter to show visible products
Step 2: Check related products and click on ‘Save’ or ‘Save and Continue Edit’ button
2. DISPLAY PRODUCT OPTIONS
You can change position of options in product page layout (for products which have options). These options can be displayed below the product information (name, short description, …) or below the product image. To configure this, go to Catalog > Manage Products, select product to edit, in Design tab, select value for ‘Display Product Options in’.
More details about catalog product in Magento, you please read here
http://www.magentocommerce.com/wiki/modules_reference/english/mage_adminhtml/catalog_product/edit