The major one being: bonus spells. I don't get'em. I'm using a half-elven ranger with a wisdom of 14 (I know his wisdom is important ... I think). I'm at level 1 right now (haven't even begun playing with him just yet), but rangers, of course, are supposed get spells at 4th level, but, on the "Spells Per Day" chart, it says "0" under the number of 0-level spells.
Can someone explain to me how bonus spells work and why that is 0?