How to I find my rss feed url?

I have a problem.

I want to add a link to subscribe to my rss feed in my sidebar.
I tried to add the widget in my sidebar, but I don’t know what to put in for the URL!
I’ve tried
http://mysite.com/feed
and other variations suggested by other users in these forums, but I can’t get it to work.
Someone told me recently that they subscribed to my site, but I have no idea how they did it, considering I have to link to subscribe on my site.
The site is at http://frogstandrecords.com
I have the front page displaying the “news” category, and I’d like for this to be the feed. Any ideas?

Thanks!