just remember it this way:
an ideal current source is represented by a nortons model:a current source in parallel witha a resistance,so when this parallel resiatnce becomes infinite then the whole of the current sourced by the current source reaches the desired location or load resistor which is the usual destination.
now coming to a voltage source,an ideal voltage source is represented by a thevenins equivalent,so when the series resistance in its path is zero then u are going to give the whole of the voltage drop across the load,without any drop across the source resistance(which is built in resistance of the voltage source).also one more important point to remember in analysing circuits is that a capacitor acts as an open circuit to dc and allows only ac,all dc voltages act as shorts.
regards
amarnath