[Victor D]

to display the first page of new products on the homepage
/modules/Whats_New/module.php
replace

if ($WhatsNew == "Y"){
    if ($config["Whats_New"]["cheat"]) $products=array();
    include $xcart_dir."/products.php";
    $config["Whats_New"]["products"] = $total_items;
    
    $smarty->clear_assign("f_products");
    $smarty->assign("navigation_script", "home.php?WhatsNew=Y");

    $smarty->clear_assign("sort_fields");
    $smarty->clear_assign("products_sort_url");
    $current_category["category_location"][] = array(func_get_langvar_by_name("lbl_wnmod_title"), "home.php?WhatsNew=Y");
}

with

if ($WhatsNew == "Y"){
    if ($config["Whats_New"]["cheat"]) $products=array();
    include $xcart_dir."/products.php";
    $config["Whats_New"]["products"] = $total_items;
    
    $smarty->clear_assign("f_products");
    $smarty->assign("navigation_script", "home.php?WhatsNew=Y");

    $smarty->clear_assign("sort_fields");
    $smarty->clear_assign("products_sort_url");
    $current_category["category_location"][] = array(func_get_langvar_by_name("lbl_wnmod_title"), "home.php?WhatsNew=Y");
} elseif ($cat==0){
    if ($config["Whats_New"]["cheat"]) $products=array();
    include $xcart_dir."/products.php";
    $config["Whats_New"]["products"] = $total_items;

    $current_category["category_location"][] = array(func_get_langvar_by_name("lbl_wnmod_title"), "home.php?WhatsNew=Y");
}

and add into your skin1/customer/main/welcome.tpl

{capture name=dialog}
{include file="customer/main/products.tpl"}
{/capture}
{include file="customer/dialog.tpl" title=$lng.lbl_products content=`$smarty.capture.dialog` products_sort_url="home.php?cat=`$cat`&"}

For a certain category check this post
http://forum.x-cart.com/showpost.php?p=266341&postcount=50