neither, both are different versions of the same idea--------integrated desktop environments with filemanagers that double as browsers and all the application associations like under windows
if youve got a fairly robust machine KDE is probably good for beginners, gnome right behind that
KDE and GNOME are fairly big, you can get rid of either with pkgtool and save some space, if your not gonna rebuild the kernel you can get rid of the kernel source too, just leave the rest of the kernel entries alone, you need those
kernel source is 175mb
KDE about 300mb roughly
gnome about 250mb
mmm.. i perfer kde, again, for comparison, search search and search.. those are such common topics that no one bothers to answer to any kind of detail anymore..