What was the name of the suite you purchased?
Here are some links which may be useful:
http://www.mcafee.com/mtp/retailcard (McAfee Total Protection)
http://www.mcafee.com/mis/retailcard (McAfee Internet Security Suite)
http://www.mcafee.com/mav/retailcard (McAfee Antivirus Plus)
Once you activated the product you can use the below instruction to login to McAfee account and install the products.
Follow the instructions written on the card - it will give you the correct URL to navigate to.