There are 39 categories of "work" that a Jew may not do on the Shabbat (or Sabbath). These represent the normal activities that give people a sense of "being in control". Shabbat is a day to recognize that G-d is really in control, which is why we "rest" from these activities on the Shabbat. The 39 categories are: 1. Planting 2. Plowing 3. Reaping 4. Binding sheaves 5. Threshing 6. Winnowing 7. Selecting 8. Grinding 9. Sifting 10. Kneading 11. Baking 12. Shearing wool 13. Washing wool 14. Beating wool 15. Dyeing 16. Spinning 17. Weaving 18. Making two loops (part of the weaving process) 19. Weaving two threads 20. Separating threads 21. Tying 22. Untying 23. Sewing 24. Tearing in order to sew 25. Trapping 26. Slaughtering 27. Flaying 28. Salting meat 29. Curing hide 30. Scraping hide 31. Cutting hide into pieces 32. Writing 33. Erasing 34. Building 35. Demolishing 36. Extinguishing a fire 37. Igniting a fire 38. Applying the finishing touches to a project 39. Transferring items from one domain to another These are the general guidelines, each group has many sub-categories. Some of these would include: Driving a car Using electricity Cooking Smoking Laundry Watering a garden Trimming bushes Picking fruit Painting Exterminating pests Fishing You can find more information at: http://tinyurl.com/2m57h7 and http://tinyurl.com/n8mr7