Can I ask if the books you are looking for are in Arabic or English?
As for the area, it is known as Downtown or "Wasat El Ballad" in Arabic.....The restaurant is known in Downtown Al Quds Restaurant Restaurant or @Jabri Restaurant Restaurant....The street name as far as I know is Al-Salt Street.
A close landmark is the post office, if it is on your left keep going forward until you reach a traffic light, there is an intersection there then take a left and the bookshop is in that street. When you reach the restaurants just ask anybody for the bookshop and they will tell you. The entrance is from the side and the bookshop is on the top floor. It is better if you take a Taxi there, if you take your car you won't find any parking.
Let me give you some names of other bookshops, because AlAhliyeh I think only sells Arabic.....
@Readers bookshop at Tajmall or @Cozmo
There is a bookshop next to the cinema at @Al Baraka Mall Sweifiyeh
They might be able to get the books for you if you request them
Send me the titles by email, and I can try and send them for you from the UK. If you want.