You need some playing experience to do it well, because:
1. the max levels is 12.
2. all 3 skills ( melee, bow and magic ) start with 1 score.
3. magic skill can not gain in the last 2 levels.
4. the WHEN to select one skill over another ta add skill point is dictated by experience. For example, even if you select archer as your character, adding score to bow first is a mistake.
After playing several times years ago, I come to the following : first I increase magic to 5 then:
a) for archer: start add points 4 points to magic then add the remainder to bow until the end so that I can use bow of the order or dragon strike.
b) for melee: magic to 5 then melee to 5 then magic to 7, the rest to bow.
c) for magic : magic to 7 melee to 5 then bow remainder (2).