There are lots of options out there in regards to adding a feed reader to your WordPress website. Depending on how you want to track and what feed readers you want to offer to uses at the click of a button will depend on which subscribe plugin you use. If you are using onsite video I would also check out the Tentblogger Viemo Youtube rss embed plugin listed below.
Feedburner.com – Now owned by Google it is a service that will track sign ups. It also keep a track of the email addresses for the people that are subscribed to your feed. If you are new to Feedburner then use the new Beta version it can give you a lot more information.