Pips from citrus will generaly grow quite easily, most grow true to type but not mandarins/clemantines they are always a new variety each time they produce seed.
They are quite easy to grow, and generaly a mandarin will be some type of mandarin, but it could be full of seeds, seedless or very bitter, or realy nice!, it depends what it was crossed from
mandarins are usualy quick to fruit (for citrus) at about 5 years, not as quick as something like key lime (2-3 years), but much faster than lemons (about 10 years) and grapefruit (about 35 years) , the important bit is to feed them a citrus feed, never water unless they are fairly dry, keep them warm and to never ever prune them (pruming will stop them fruiting)
The best way to germinate , takes a few days, in a plastic bag, betwen paper towel soaked in water, leave it over night, then crack the outer shell off the seed, then leave it inbetween the paper towel at about 27C , check every day and after a few days it will grow a nice straight root one way and a shoot the other way, at that point plant it in perlite and citrus compost 50/50