Shrinking an input signal for the ADC
Like Olin said, a voltage divider will do nicely. Keep in mind however that the ADC input impedance is in parallel to the lower resistor and that it may influence your divider ratio; ADCs often have rather lower input impedance. You can buffer the divider's output with an high input impedance buffer like an opamp.  



The LT1677 can operate from a single supply and has rail-to-rail input and output. Since you don't need to sample at high sample rates I presume that the bandwidth of the LT1677 is wide enough to cope with the impulses.