If this is for ISAPI_Rewrite 3 on our Windows 2008 servers, then yes you just need to upload the .htaccess file to your web space the same as any other file for your website using FTP.
The .htaccess file needs to be placed in the folder where you want to use URL Rewriting. It also effects sub folders, so if you ant it to apply throughout yoiur site place the .htaccess file in your wwwroot folder. You do not need to edit your web.config file.
The page below gives some common examples to help you get started with ISAPI_Rewrite 3:-
http://www.helicontech.com/isapi_rewrite/doc/examples.htm