Maple w/ maple fretboard? Raw or oil finish? If so, OOOO steel wool the neck & frets to clean them. Then,
1) Apply Birchwood Casey gunstock oil.
2) Allow oil to dry. 24-72 hours is usually good.
3) OOOO steel wool again and wipe down with a tack cloth.
4) Repeat steps 1-3 until you get your desired finish.
2-5 coats will usually get you there. It is a good idea to remove the neck from the rest of the guitar to avoid getting metal shavings from the steel wool in your electronics. I have read about people using Scotch Brite? pads instead of steel wool but I haven't personally tried them.
I have done this to raw maple necks (mostly Wolfgang's) for years with great results. Pretty sure Ernie Ball uses BC gunstock oil on some of their necks.
If your fretboard is rosewood or maple do everything listed above, EXCEPT for applying the gunstock oil to the fretboard. Only use the gunstock oil on maple or maybe mahogany when talking about necks.
After you have that original finish done you may want to clean, oil, OOOO again once or twice a year dpending on how much you play and how quick the neck starts looking dirty. 1-2 coats usually works here as routine maintenance.