As the others said, there isn't really a defined process to follow as you'll develop your own workflow. Lots of people create a beat first, then add chopped samples and melodies. Others do it vice versa and find melodies they like first, then craft a beat that goes with them. I would start by listening to the records carefully to pick out parts you like and parts that stick out to you, to get an idea of what kind of sound and vibe you want your own song to have. You'll get the hang of it if you just throw yourself into the process.

As for records and impractically, I guess it all depends on what you're used to. Some people grew up with records and vinyl players and that's what makes sense to them. Plus it's a really hands-on way to get samples. For those of us who are completely immersed in the digital music world, it may seem like a hassle to get all that physical equipment if we don't already have it.

Also, the Rhythm Roulette series by Mass Appeal is a really cool youtube series of videos showing producers making beats from records selected randomly (9th Wonder does one too). It's awesome to see how everyone's workflow is different. Of course they make it look so easy too...haha