my sister has over a thousand cd's.
i go to her house, get drunk and listen to music with her and her husband.
if i hear something i like, i take it home and put it in soundforge.
then into Reason.
ive never sampled from vinyl, although i own about 30 records ive bought from goodwill for sampling.
if i was going to sample from vinyl...
i would put the record on the turntable, hook the turntable up to my computer, and record the part i wanted into soundforge.
you can cut it up in soundforge and assign each section to different keys in Reason or whatever sequecing track you use, to 'play' the sections.
to get a good bass from vinyl samples...
EQ the sample. take all the highs out. then maybe add some compression, and you have a bass line that matches the melody.
i use a lot of vocal samples from old TV shows and movies. as kind of a solliquie in or before the lyrics.
heres a great website with thousands of vocal samples...
http://www.dailywav.com
ive never sampled from vinyl, but thats the process ive understood others to use.
if im wrong, maybe someone more knowledgable in this department can correct me.
.peace.