Be careful with oils that don't dry. They can soften the wood over time, and build up under the frets. This can make frets loosen, and make re-frets more difficult. Just apply the minimum amount possible, and only once or twice per year. Most "lemon" oils are just naptha, or a similar base, with some additives. Those really don't confer any long-lasting effect, as they dry up quickly. Some of the bore or more expensive oils will stick around, though.
I just use a humidifier to keep the wood from drying in the winter. That is the ideal method, I think. I don't know if the formulation is still the same, but luthier who made my guitars (Terry McInturff) always recommended Watco "Danish Oil" if necessary, to keep the wood looking good. However, he only recommended one or two applications per year, and advised that, no matter what, the wood can still dry out if not sealed, or kept in a humidified space. Moisture still escapes an oiled board. As always, some recommend that you never oil the board.
TGP has a ton of debate on the subject