First, the word "sample" can be used as a noun and a verb. The question actually uses the word both ways. The phrase "grab the sample to record and chop" actually is "sampling" - the verb - this is what you are doing to the original song. Of course, "the sample" in the same phrase, is the noun.
In order to "grab the sample", this implies that you already have a song in mind that you want to sample from. So, "the sample to record and chop" as used here in this question, is actually a smaller part of a song that you want to use elsewhere.
How do you Sample (verb)?
To "grab the sample" is "sampling" and this requires some way of capturing the part of the original song that we are interested in. Since I do most of my work on my computer, I use digital recording software programs to record the part(s) of the original song that I want into different files. Regardless of what the original song's format, I want the format of my samples to be .WAV because this format is more common across different programs and digital devices.
I usually work with hi-quailty MP3s or WAV files and load them into a WAV editor - almost any program will do. I use Soundforge 8, Audacity, Adobe Audition and Cool Edit Pro to record samples from CDs, vinyl. I use BeatCreator and Recycle 2.1 to chop my samples.
Sampling is really just a matter of listening to a song, identifying the parts you want to sample and then cutting those parts out to make your sample slices from. Once you have your samples, you can load them into Reason devices such as the NN-19, NN-XT, DrRex and ReDrum, which can play back the samples and provide different levels of control over the playback of the samples.
The above video shows how I created a sample flip beat using a sample captured from an MP3 file. I used Sony Sound Forge to capture the sample. After that, i used Propellerhead ReCycle to make the sample slices. Then, I imported the sample slices (a .RX2 file) into Propellerhead Reason's NNXT Advanced Sampler, where I do the actual "sample flipping" or re-arranging of the sample slices over the beat I made.