Log onto your feedburner.google.com account
Click on the feed you need the id for
Right bellow feed title click on Edit Feed Details…
Your feed id can be found in the text field box to the right of Feed Address http://feeds.feedburner.com/
To find your FeedBurner url:
From the exmaple above Feedburner url is the full Feed Adress:
e.g. http://feeds.feedburner.com/WpTubePlatinum
