The IDE connectors usually have a notch in them, so they would be impossible to mount the wrong way around...
However, if the notches are missing, the red wire ( pin one ) on the cable should be closest to the power connector.
The floppy could be trickier.. I have encountered a bunch, and none of them seemed to have the same standard...
Some wants to be connected to the first connector on the cable, some on the second... And pin one seems to vary depending on manufacturer as well, but just try all the possible combinations... You wont damage anything, so long as the computer is powered off while you disconnect/reconnect cables.
