For example I have a {Stuffy Doll} on the feild and it is damaged by a {Harvester of Souls},will it die,or will it survive the combat phase and deal 4 damage to my opponent?
704.5h (http://imtgapp.com/forum/index.php?action=imtg;area=rule;number=704.5h): If a creature has toughness greater than 0, and it's been dealt damage by a source with deathtouch since the last time state-based actions were checked, that creature is destroyed. Regeneration can replace this event.
The key word to look at is DESTROYED. Stuffy cannot be destroyed therefore deathtouch would not send him to the graveyard. The damage would have no effect and stuffy would trigger to deal damage.
Actually, this kind of thing happens in mtg a lot. So, ill add this on the back end of my previous post.
101.2. (http://imtgapp.com/forum/index.php?action=imtg;area=rule;number=101.2.): When a rule or effect allows or directs something to happen, and another effect states that it can't happen, the "can't" effect takes precedence.
Example: If one effect reads "You may play an additional land this turn" and another reads "You can't play land cards this turn," the effect that precludes you from playing lands wins.