Rails and RSS Feeds

Hello Everyone,

I wanted to know something about RSS Feed readers in Rails. I just
started reading up today. Have some really basic questions. Let's take
the example of a multi-author blog. Blog owner is Person X. Blog posts
are being posted by Person X, Y and Z. And I subscribe to the RSS feed
of this blog through my rails application.

Can I:
1. Know that a particular post was posted by whom? (X / Y / Z).
2. If yes to answer 1, what all can I know? His name? Can I extract
photo too?
3. Can I know that a particular blog is being owned by whom?
4. If yes to answer 3, what all can I know? His name? Can I extract
photo too?
5. For a particular blogpost, can I extract the tags that the blogpost
has been tagged?

More questions:
6. Which is the best gem / plugin that you know to be used for a rss
feed and parsing the feed content?

Any help would be appreciated.
Thanks in advance.

Regards
RP