Hmm, it almsot depends on what your use of herbs will be for, I would imagine.
(edit: it's early and I missed the "nourishing" word in your original post, so, my first recommendations are probably the best.
If you want nourishing infusions for your own health to drink, Nettle and Oatstraw are two of my favorite (as well as Red Clover & Comfrey for many friends).
However, if you are using the herbs for trinctures (or Glycerides or syrups, etc) or salves, then that will change the type of herbs you'd purchase. Comfrey is excellent for healing wounds, I know a friend who goes through roasted dandelion root like crazy, and another who can't harvest enough Plantain for the salves she makes and gives away. Your milage may vary.
Here's a good overview of different herbs, but I'm sure the other Wise Women here can chime in as well. viewtopic.php?f=7&t=15
I mostly stick to infusions, (and salves in small batches), so in my case "Nettle" is really the only thing I buy in bulk like that.
There's also the some good info around teh other areas of Susun's site for reference:http://www.susunweed.com/Weed_letter_Archive.htmhttp://www.herbshealing.com/Articles_Susun_Weed.htmhttp://www.blubrry.com/beyond50/401379/ ... infusions/