Just finished reading the Force Awakens novelization by Alan Dean Foster.
I will say in some areas, the author coasted off of the visuals the movie offers leaving the book as a stand alone representation slightly lacking for me, HOWEVER..
..it also certainly fills in a lot of grey areas. The dialogue is much richer in some sections and there are small parts of scenes that transpire slightly different. You also get to know the names of everything, and there's even some psuedo-science explanation for Starkiller bases workings (its not actually using the stars energy for the weapon burst itself, the stars energy is a means to attract dark matter, which is what is the actual fuel to the beam so to speak and has to do with how it fires "through hyperspace in real time" as somewhat explained in the text.
ANYWAYS, its well worth the read to fill some things in and get different views of some parts as well.
There are also smaller short scenes entirely absent from the movie in the book.
I also feel the books lends more credit to the Rey is Lukes daughter theory (possibly personal skew!)