Held+1 to Bib's explanation of
Held. It's one of those risk/reward cards that may find use if Frodo does a bit of fighting for you, and if your deck heals better than if removes burdens (or if game situations present a sudden allergy to using the ring). If you decide to use
Held, there are plenty of cards that can wound/discard minions so that you can get rid of it (Gondor and Rohan do this very well). Direct wounding in skirmishes can help clear minions, too (ex.
Mind Your Own Affairs adds lets you do this without putting on the ring). In Towers Standard format,
Sleep, Caradhras would also nix it.
Healing with tokens
Spotting culture tokens to heal - the card that comes to mind is
Ring of Barahir. In any case, while it is your turn, your shadow cards are inactive, so it would only apply to your free peoples characters. Your opponent's minions can't make use of your card's text, so minions couldn't heal doing this. Likewise, during your opponent's turn, your free peoples cards are inactive, so spotting a shadow culture token wouldn't heal your minions (
Arrow from the South and
Scaling Ladder are two shadow cards that come to mind for using tokens to heal minions).
Site Control
I like searching card databases and some retail sites if I'm looking for a card with a certain text. Searching here at TLHH is good - I have also found ccg-singles.com to be a handy resource (ex. typing "take control site" will bring up any card printed from all sets.
Hope this is useful - all the best to you!