I can't remember the name of two books..

[Xamius]

1. An old man and his wife are raising a child in the woods that apparently came from "the other side" of some dark line that is slowly moving forward. Apparently the child has some sort of emblem or necklace of unknown origins (can't remember if that's actually right). I think this couple saw the child being dropped off in their wide by some guy on a horse from the dark side of the line.

Now book #2

2. In the end of the book, the main character is magically transported to the camp of whomever they are fighting and becomes a slave along with others. I think this might be part of the far seer trilogy, I'm not sure. It was the first book of whatever trilogy.

[Ochos]

was it a dwarf living under the city, the child was dropped of from the other side of a moving line. the other side contained all the faery folk and mythical type creatures who decide enough is enough, and declare war on the humans. the child grows really quick, and goes into the deepest tunnels to some sacred dwarven cavern. theres also a race of little people living in the city, who ride various animals.
more of a description, but for the life of me i cant remember the name of the book

[Ochos]

GOT IT!!!!!! i think, is it Shadowmarch by Tad Williams?

[Whiskeyjack]

That second book sounds like Magician Apprentice by Raymond Feist... where Pug is enslaved on the other side of the Rift and becomes a master magician in book two.

[Yezarul]

1. An old man and his wife are raising a child in the woods that apparently came from "the other side" of some dark line that is slowly moving forward. Apparently the child has some sort of emblem or necklace of unknown origins (can't remember if that's actually right). I think this couple saw the child being dropped off in their wide by some guy on a horse from the dark side of the line.

Now book #2

2. In the end of the book, the main character is magically transported to the camp of whomever they are fighting and becomes a slave along with others. I think this might be part of the far seer trilogy, I'm not sure. It was the first book of whatever trilogy.

I'm thinking Wizard's First Rule by Terry Goodkind for the first one

for number 2:
the person above me sounds like it's probably Magician's Apprentice. Does the book start off with a kid that happens upon a wizard and ranger then as he grows up he becomes a wizard?