It's mainly about getting to know your oils and how they benefit and how they are to be used. I read in Wood & Steel (I believe) that BLO is good to use, but you only need to use is sparingly in the life of the guitar. In fact they stated that if you use it maybe only once a year, after a couple of years you shouldn't have to use it again. Whatever you use, it can be and should be used on the bridge and truss rod covers as well.
I use mineral oil on mine. Caution, not all mineral oils are good for this, use the laxative kind. It's good for what ails ya! Mineral oil, however, will evaporate so it needs to be re-applied from time to time. I do this probably every six-nine months when I change my strings. Whatever product you use make sure you thoroughly wipe up any excess, AND make sure you properly clean your fretboard before oiling it.