How do you correlate voltage output with these values that I have collected?
It looks like it's a 10 bit ADC supplied by 3.3V (checkout the datasheet for the ARM7 part on the logomatic: http://www.nxp.com/documents/data_sheet/LPC2141_42_44_46_48.pdf).  That means that a value of 1023 corresponds to 3.3V.  0 corresponds to GND.  It's a linear scale so all you have to do is scale the numbers you see in the ASCII file (e.g. Voltage = Value * 3.3V / 1023).  As to the "weird" file I don't think there's anything weird about it.  Without digging in too hard it's dumping binary data to the file, which isn't readable in clear text (e.g. ASCII).  So your text editor interprets the binary data as ASCII and gets "weird" characters.  You'd have to write a script/program or something to parse the binary to interpret the data.  Scaling would be the same.