If you have a supply of recipes and ingredients, you can level provisioning in less that an hour. This tome suggests recommendations on leveling recipes, their ingredients, and links to sources of ingredients.
It is fun to learn by Alchemy by trial and error and hope whatever ever does not kills you makes you smarter. However, an Alchemical Poison Recipe book does reassure an aging mind of success and less of death.
Tip: Doing master writs? Start with the name of the poison and scroll down until you find the other traits.