Line height is the space between one line and another and you would set it to whatever suits your design the best but generally 1.5 times the font-size would give the text room to breathe. (1 x font-size would be to close and lines would almost run into each other.)
Not really sure what you are asking as there is no real correlation between line-height and the resolution you use. Changing the resolution changes the way the whole page fits on the screen and affects everything in the same manner. Although I guess you didn't really mean resolution but perhaps width or something similar.
If I use a wrapper width 1024 px, what is the best line-height?
Thanks a lot.
It depends on the size of the text. The wrapper size doesn't make much difference except that at large widths perhaps you wouldn't want the lines too close together as they would be hard to read. Longer lines are hard to read if they are close together so its best not to have lines that are too long or are too close together.
You can find more specific details here:
Generally I set a line-height on the body of about 1.4 or 1.5 which gives breathing space to the text for most uses.