Definitely.
While DF 40d doesn´t have many of the goodies that 0.31 possesses it is definitely better for beginners to learn stuff.
It is already well covered by the DF Wki, and has less bugs, as others already mentioned,
and concerning military things it isn´t as difficult as 0.31.
In 0.31 the marksdwarves bug forces you to go melee
(even if you get your marksdwarves to work in 0.31,
the wounds their arrows/bolts cause to their enemies are usually minimal...it takes lots of arrows/bolts to down even a single goblin.
Even ballistae are underpowered in 0.31...in 40d a single ballista bolt could wound/kill several goblins at once...in 0.31 it might glance off the silk clothing of the first goblin it hits
)
And due to the new material system melee in 0.31 is also much more deadly than in previous versions.
In previous versions you could often survive an ambush by a few goblin melee fighters even with no marksdwarves just by assigning a lot of dwarves and ordering them to swarm the goblins.
In 0.31 however dwarves without strong metal armor and adequate weapons are dead meat against goblins with metal armor and weapons and even a squad of just 5 pike goblins can mean the death of a fortress of 30-50 dwarves, if the fortress isn´t already well prepared (with a standing military that is adequately armed/armored and/or adequate trap coverage) .
So, yes, for learning DF basics better try 40d