At CSS Vault, you can download style sheets for all sorts of purposes.
http://www.cssvault.com
http://www.Download.com is a great place to download software, including different versions of popular browsers:
http://www.download.com
If you want to include a script (in JavaScript or another language) in your Web page, but you don't know how or want to write it yourself, look to this site for a collection of stock scripts to use on Web pages:
http://www.hotscripts.com