get a rca (x2) > miniplug (1/8") adaptor - male to male. then get some adaptors, two of each - rca female > 1/4" male, rca female > xlr male. that should cover most boards. you can also get a mini > mini and a mini > 1/4" adaptor in case you get a stereo headphone out.
as always, check through the archive for more info on this but that should get you started.