Basically, it starts as a variation on the seahorse, once the ova are fertilized within the mother the embryoes are drawn back into the father who then carries them to term (there's actually a second, more gruesome stage to the process but that's probably a question for another time.) How w(c)ould this be done in a species of land-dwelling bipeds (still working on whether they're warm or cold-blodded)?
On Earth, the marsupials like kangaroos or koalas have an interresting system: the gestation period is very short, but they give birth to an undeveloped foetus that climbs by itself into the mother's pouch and keeps growing there, feeding from a nipple within this pocket. The male of some species like the tasmanian tiger even have a pouch too, although they do not use it for the babies. The obvious advantages are that the female is much less likely to die while giving birth, and is ready to be impregnated again after a short time.
If you go for an egg-laying species, the easiest I believe would be to have the female lay her eggs in the male's pouch with an appendage, the ovipositor. This is very similar to the seahorse system.
For a live-bearing species, the female could also give birth to the foetus with an appendage directly into the male's pouch. Or she can give birth to an undeveloped foetus that has to go by itself onto the male, then in his pouch. This implies that a kind of secondary sexual intercourse is required for the female to give birth. Lastly, the male can simply pick the newborn foetus and place it in his pouch.
Now, depending on how evolved your land-dwelling bipeds are, there could be a lot of specifics or rituals to each solution. Anyway it's either the female give the youngs to the male, the male takes the young from the female or the youngs go by themselves from the female to the male. There could also be a third party that take the youngs from the female and give them to the male, but this makes a minimum of three individuals for a natural reproduction.