http://www.zhlt.info/You will find list of every compile parameter there and its function.
The only compile command that is strictly -necessary- for NS mapping is adding
-hullfile C:\Steam\SteamApps\yourusername\half-life\nsp\nshulls.txt as a HLCSG parameter. Change the path as necessary; it must point toward your nshulls.txt that comes with NS.
The main other commands are:
-fast & -full, for HLVIS. These speed up compiling and slow it down respectively. NEVER release a map that has been compiled with -fast.
-extra for HLRAD - this makes your lighting look prettier but takes longer.
Beyond that, anything you add to the compile parameters should be purely on a per-map basis and thus is at your own discretion.