I suggest that zero cameras would be too few.
Being that this topic is in the "Entry Digital Photography" section, I feel that one camera is ideal for someone starting out in photography, digital or otherwise. This may not apply if the user is simply making the switch from analog to digital.
Years ago, a wise man suggested to me that one camera/one lens is the best approach early on in the learning process.
Master the one lens/focal length (this was before zooms were so common place) before moving on to another focal length.
It's sad to witness users with more dollars than sense, walking about with a bag overflowing with lenses and when they show you their work.... well, it's underwhelming to say the least.