To redirect a website/URL to another is a fairly simple process. It is achieved by creating an .htaccess file in the folder you wish to redirect.
Step #1: Create the .htaccess file (it's just a text file -- you can use Notepad) and add a redirect line. For example the entire .htaccess file could simply read:
Redirect /oldfolder http://www.yoursite.com/newfolder/
Step #2: Upload the .htaccess file to the web site via FTP (you can place the .htaccess file in a subfolder or the root folder depending on if you want to redirect just a subfolder or the entire domain).
Here are a few helpful links on the topic:
Additionally, the ".htaccess" file is far more than a simple redirect (as the
last link above will show) you can use it to do things like rewrite URL's,
set up customized error documents and more.