Any wave editor is suitable for chopping, as long as the chops are clean(no clicks). As pointed out, by chopping on the zero point of the wave file(the point it crosses the line), and also on time. The first hit point of each chop has to be spot on. Taking the extra time to get clean chops is key. Then arrange the chops on seperate keys on a sampler and then play chops off of each other till you have something going on, record it.
Add drums if necessary, a little salt, maybe some pepper, and you are on your way to a recipe for a decent beat.
Understanding the key of a sample is important, tuning your ears to hear the different keys will take time, but will always get better the more you practice. Try using a patch of a piano and improvising to the sample, trying to hear which keys of the piano match the keys of the sample. Once you know the keys you can then add melodies or bass etc to phatten up the sample and make the peices work as a whole. This is a process that comes only with practice, there is no quick fix solution. So keep at it and I promise you will only get better and learn more of the process of getting chops to work together. Once you know this you can then get samples from any source and start mixing and matching and recreating. Practice practice practice.