best practice for file locations

[Brian Carey]

Hi,

I'm a little confused about the relationship between conf files in 
conf.d vs sites-enabled. Should server configurations be set up in one 
directory or both? If either is there a "best practice" location? If 
there are conf files in both locations which takes precedence? Some 
sources I've read/seen seem to use one and others seem to use the other.

Thanks,

biscotty