Need a mass data upload solution (data feed, etc)

I have a website that I need to have populated with several thousand products. I need to have the product uploaded, the description and details uploaded, etc ASAP. I imagine the fastest way to do this would be to incorporate some kind of data feed, if possible. I am open to any solution (does not HAVE to be datafeed, however I need it as quickly as possible, and it needs to be able to work in the future when making updates as well). For instance, writing a script that will take an excel spreadsheet and feed the site. I will create the excel spreadsheet. Here are some other details you may find pertinent: The website is located at [login to view URL] It is an osCommerce (php) coded site. I will need this to be a solution I can use to modify the products listing again in the future. I need this done ASAP. Please reply if you can do this.