@Heavenfall - it is a matter of information density. Some things are suitable to get small blurbs on stat summaries and the like. And some things should be explained in noob-friendly, long detail. The later is the domain of the right-click.
For example, clicking on the mana types, say death, would give a complete breakdown of the benefits gained at 1 pick, all the way through to 11 picks.
1 - 3 common spells in spellbook
2 - 5 common spells in spellbook
3 - 6 common, 1 uncommon spells in spellbook
4 - ...
...
11 - all spells in spellbook, start game knowing 2 common and 1 uncommon spell