how to sample thm correctly...and how to make it sound unchoppy??
any help or suggestions....?

"Synth" is a pretty loaded term. It can refer to any sound that's being processed (or synthesized) into another sound. I refer to some of the tracks in my mixes as "synth parts", even though I haven't touched a hardware "Synthesizer" in years. I'm using synth in that case to refer to something I've sampled and then heavily processed (delay + verb + stretch + shift + reverse + etc...) so that it sounds like swelling noise or like something a Synthesizer would make.

So what I'm saying is I'm not sure what exactly you mean by synth. I'll make a few guesses though:

If you're sampling something that's "80's Synthtastic!", say something like A-Ha or Wham! or any other of the vast number of synth-driven 80's bands (something that has really clangy, sharp stab sounding synths), you'll probably want to put a nice wash of reverb on your chops, to make them sound smooth. A slight delay can work very well, too.

If you're trying to chop up some longer swells, or 'pads', of music, you can use the same trick. Use some reverb or delay to soften the edges of your samples. Another nice trick if you're using a long swell (I'm just assuming you're taking a long swell sound, and you want to resample it at a couple of different pitches, so you can create sort of chord progression), instead of just hitting "RECORD" to end the sampling process, fade the sound out with "level adjust" down to zero, then stop the recording. That way you won't have any hard edges.

Like I said, I have no idea if these scenarios are specifically helpful in what you're trying to do. Let me know.

*edit*
huph beat me to it.