The Winter Soldier is none other than Bucky Barnes. His transformation into this role was a result of manipulation and experimentation. Despite his past actions, he later strives for redemption and works to atone for his deeds.
Yes, the Winter Soldier comic is considered canon within the Marvel Comics universe. It plays an important role in shaping the character's story and continuity.
The Winter Soldier's age in the comic varies depending on the specific storyline and continuity. But typically, he's depicted as being in his 30s or 40s.