What career specing does for you character...
Okay, I got my copy of the game and thumbed through the manual and for once, their's something in there that's actually interesting to know!
When you add a point into a career line, all baseline spells you have in that line get upgraded by one level. So, if your level 20, and you have 4 points into Line A, all associated skills in Line A are treated as if your character where level 24. Or so the manual implies.
In the end, this might mean that if you fully spec into a line, the 3-6 abilities you have associated with that line will be treated as level 55 spells, instead of level 40 spells. Remember, spells upgrade automatically as you level, all spells normally cast at your level unless they don't upgrade at all. (i.e. The PBAE Root in all 3 Range DPS Lines) Note, this is only for the baseline abilities they mention, I don't know about the abilities you can unlock in those lines.
Go to the WarDB to get an idea of how Spells/Abilities upgrade with your level. Then look at the career builder and see what lines are affect what spells. I figure it'll be important to learn this over time. Luckly, we can always respec for a modest cost.
DAOC Midgard Percival - Guild Nordvegr
Leyali, RR10 Valkyrie
Warhammer Destruction Phoenix Throne - Guild Warvegr
Sentack, Disciple of Khaine