By "BS and LS" do you mean assessment of bowel sounds and lung sounds?
Reviewing a physical assessment textbook like Jarvis or Bates is a start.
Check libraries at any nursing school
for the videos on these skills. Even if you are not presently a student there, you may be still be able to view the videos in the library.
There is a pretty cool website:
The Auscultation Assistant- Hear Heart Murmurs, Heart Sounds,...
Then practice, practice, practice.!!
If you DIDN'T mean bowel sounds and lung sounds, ..oops.!!!
Good luck with your search.