The thing about Ryzom that is so great is, you can do it either way, or any other way -- however you like it.
The most common thing for people to do is pick one branch or line from each parent skill -- for instance, going with 2H melee fighting in Fight, Defensive Afflictions in magic, Armor crafting in Craft, and Forest Foraging in Harvest. Then they work those up pretty heavily, with occasional diversions into other skills as they desire. After capping out those first skills, then they go back and branch further out in one or more skills (e.g., going into weapon crafting once you are done with armor).
Doing it that way, my experience at least to the low 100s is you would always be slightly hurting for skill points. That's because for every 5 levels (50 skill points), there are for most skill branches, 3-4 upgrades. That means about 35 of every 50 Skill Points goes into things like upping focus, or the like, rather than learning new actual skills. Fight is the most extreme example of this... needing 4 stat upgrades (HP, stamina, and the two regens) every 5 levels, more or less. If you just level one fight skill, that gives you only 10 points every 5 levels to buy things like "Accurate Attack."
My preferred method, therefore, is doing 2 lines per skill. I find if I do that, it works out better for my play style (note: I only can speak to MY style, not anyone else's). For Fight this was easy -- I just dual wield. I use the Sword skill points to buy upgrades, which consumes most of them, but the close/dagger skill points can then be used to buy things like Attack After Parry and so forth. For Harvest, similarly, I have levelled both Desert and Forest foraging, with desert ahead a bit (121 vs. 112 or something)... I use the higher one to get the "upgrades" like counterpart and focus, and the lower one to branch out and get specializations like "Zun Amber Prospecting."
The advantage of the second way is that you have plenty of skill points for your level. However, the DIS-advantage is, it takes longer to level. I am 108 in both 1H slashing and Close Combat (dagger) skill, but if I had used say a shield and just worked 1H slashing, I'd probably be approaching level 200 in that, since the XP is being split between 'em. And in the same vein, I'd probably be nearing 200 desert forage instead of being back at 120, if I hadn't spent half my time foraging in the forest. However, although I'd have all the improvements, I'd have half as many stanzas (or less) in those skills as I do now.
So, it all depends on play style and what you like to do. I like to have variety, so I go for more branching earlier. Some people like to specialize more.
Hopefully that was more helpful than confusing.
C