Repairing old guitars.

My lil brother was given an old acoustic Dulcet Classic rose-martin, or something like that. It needs some work but I don't have the time to go to a music shop, or the money. If you can help me id like to know;
1. Can you get scratches out of the guitar, if so how?
2. What strings to get.
3. Is the nut supposed to be a few centimeters to the left, if not how to put it back correctly.

1. Who cares about scratches? IMHO (See Willie Nelson's guitar)
2. Nothing too heavy, so it doesn't warp. Get some 10's to start just in case, for lower tension. I like D'Addario Phosphor Bronze Extra Light.
3. If the strings run along the edge of the neck in a straight line you are cool. If not tap on the side of the nut with something solid but light like a drumstick or something until the strings line up. If it is slid to the side that means there is no glue holding it in place. You can use a little amount of white glue under it to get it to stick, but this is not necesary.

Trigger