As many as you want to and are interested in leveling.

Personally, I plan to invest heavily in maybe one or two crafting trees then make sure I have points distributed where I want them in various class, weapon, armor, guild, racial trees, etc. then use the leftover points to dump into random crafting stuff here and there. I think I read that the total number of skill points you can get by leveling, getting all the shards and from quests is something in the area of 200+, maybe upwards of 300. I could be wrong though.

Either way, you generally have a lot of points to play with, plus you could always respec if you find that you spent points on something you don't want anymore.