It depends on the man! I have tasted a few men's ejaculate, and it ranges from not bad, sort of sweet-and-salty, to not salty at all and the taste of three-day-old coffee.
Encourage him to eat pineapple, green vegetables, and just healthy sugars in general. Those are said to make the taste sweeter.
You are so right (about the pineapple). I dont know if you guys know this, but it is all about what he eats, and vice versa. I have never let a man ejaculate in my mouth. There was this one time while giving oral sex that my fiance did, and I bit his pecker. I have heard it from several people that I know, that it tastes like milk and salt. I dont know what thats all about, but whatever floats your boat. Have him eat the sweetest fruits that you like.
This may sound a bit silly ... but I know from a male perspective that ejaculating into a womans mouth can be a bit overwhelming for them the first time. There is the taste and consistency ... but don't forget that it shoots out with a reasonable amount of force.
Two things that I doubt that any guy would object to if you asked (so don't be embarassed to do so):
1) Ask him to warn you just before he ejaculates so you can angle it away from your throat to keep from gagging.
2) Ask him to ejaculate into a tissue, towel, etc. either from masturbating or giving him a hand job. Then you can taste a small bit to see what it is like before trying a full load.