When you program instruments using Live's Sampler you often have the problem that the groove or melody you have sounds too static. You can overcome this by using different velocities of a sample or using a technique called Round Robin, where there a different versions of the same sample which change every note.
To get to play a sample (or versions of a sample) in Sampler is quite easy. Drag the samples you want to use to Sampler's "Zone" and click the VEL switch. Then select all the samples, rightclick and select "Spread Even". A drawback is that this conflicts, if you want to have the volume influenced by velocity.
To get a Round Robin function is a bit more complex than velocity switching. Instead of VEL click the SEL switch. Then select all samples, right click and "Spread Even".
Next you have to go to Sampler's "modulation" tab. Activate an LFO, as type select "Sample&Hold". Next set the rate to SYNC and beats to something like 1/32 (edit: actually this is irrelevant, if you turn RETRIG on). As target A select "Sample Selector" and set the intensity to 100%.
Now if you trigger the sample there should be a different sound on each note.