First of all: Obviously this is a very disturbing story, about a woman and child held captive in a shed, and (spoilers? It's in the trailer!) how they escape and adjust to the world. That said, it wasn't as difficult to watch as I had feared; there was a lot of humor and beauty interlaced with the more painful material. If you are particularly bothered by a piece of the content - children in peril, stories involving sexual assault, etc. - you probably want to avoid this, but otherwise, I think it's worth watching, especially for the performances of Brie Larson and young Jacob Tremblay.
Availability: In theaters, though it was pretty hard to find.
Best Picture: Nah. The movie as a whole just didn't work for me as well as other Best Picture nominees did, though it was very affecting in the moment, completely terrifying at one point, and had some very good performances. But immediately after I finished watching, I started thinking "Hm, I wish it had done xyz instead" or "Wait, how did that...?" I do still think it's worth seeing, but I don't think it's the best movie of the year.
Actress in a Leading Role: YES. Pretty much the entire movie rests on Brie Larson and Jacob Tremblay's performances, and they were both amazing. (He really should have been nominated as well.) Larson takes a character that could have easily been reduced to one-dimensional victim and makes her very complex and interesting.
Directing: Um, sure. I think the directing deserves some of the credit for the strength of the portrayal of Jack (the little boy)'s unique worldview, and for letting quiet moments and subtle performances have a lot of power.
Adapted Screenplay: I will probably revise this after I read the book - I'm on the hold list for it at the library - but I think they did a good job of retaining Jack's distinctive point of view. Unfortunately, I think this was to the detriment of really making the story work as a story (which could well be a problem with the book, too). There were many times when I felt like the audience needed information Jack didn't have.