...if I were to connect RCA male plugs to the output speaker wire would that be capable of transferring audio signal through the receiver at the RCA input ports? Or is there a different voltage/power/signal needed to perform this function?
While a newbie question, it's a good one.
The audio that comes to speakers is typically amplified audio which carries far more current than RCA line level connections use.
If you search on eBay, you can find speaker level to line level converters easily enough. Clearly though, the solution of just using a headphone (1/8" mini stereo) to RCA adapter (linked above) is the way to go.
There are also other iPod docks available which have built in RCA outputs with remotes, and even on-screen interfaces which are available.