how to insert RSS info correctly

For some reason RSS is more complicated to me then it probably should be.

I cannot find out how to create a simple subscribe button without using a plug in.

There is a place on my site for putting RSS info but I am not sure what to put there.

Articles I read are all different or very vague on the exact solution.

Is it

site.com/feed/

or is it

site.com/?feed=rss

or something else?

Now, I am being told to put something like

feedburner.com/site

Which is even more confusing.

What should I put under:

>Philanthropy

>General

>RSS

?

Thank you for your time! Greatly appreciated!