We were just there this past weekend with DS (6mo).
We have a Bjorn (fortunately with the extra back support) and he was actually able to ride many rides in that, generally anything where there isn't a lap bar (like the carousel, teacups, (on which he was indifferent, and almost fell asleep) pirates, IASW Casey jr and the subs)
his favorite rides were Casey jr and Nemo.
After about 2 hours of rides with him, he crashed in the stroller and we did grownup rides. there were three of us.
Rideswap varies by ride, but generally you go to the ride entrance or FP return and present the whole party. They give you a pass and then all but one or two adults get in line and ride. The stroller watcher is free to meander while the rest are on the ride, and I took a lot of pictures while I waited for rides. We switched of who watched and who rode first throughout the trip. the rideswap pass is good for two adults and is specific to each ride.
It will tell you on the pass where to go to board. On many attractions it is the FP return, but on Space it's through the exit, on TSMM it is through the disabled rider entrance, and on the matterhorn it's at the entrance to the line switchbacks at the control tower. In general, if you're not sure, ask the CM where to go.
It's worth noting that TSMM is an exception to the rule about only having stroller passes on height restricted ride. They made a point of telling us he could ride, but he was sleeping in the stroller, so they gave us a pass and I sat with 10-15 other full strollers watching Mr. Potatohead.
The pass is good all day and we even went back the next day when we had to run off for a feeding right after half our party rode one ride.
Also, since we had three adults, one lucky person rode twice on each attraction.