For each tier (you're currently in T1) you should find the following harvestables:
'hard' ore node - 4 items (2 common, 2 rare)
'soft' ore node - 4 items (2 common, 2 rare)
root node - 2 items (1 common, 1 rare)
wood node - 2 items (1 common, 1 rare)
shrub node - 5 items (4 food, 1 rare root)
fishing node - 2 or 3 items (different named fish - all common)
in addition, any node can also supply an item described as 'glowing' or sparkling' etc. - these items count as rares (or uncommons) and carry a single different adjective for each tier.
This should give you a total of 20 or 21 possible unique items. The common ones have a average broker value of about 1CP, so a full stack of 200 will only net you a couple silver. IMHO, the commons are really not worth storing unless you plan to craft with them yourself.
The rares on the other hand, even the T1 rares, should earn you a tidy profit if you sell them on the broker. I would say dump any commons you don't plan to craft with and only store the rares.
How will you know if you pull a rare harvest out of a node? The game dialog will tell you and you'll get an audio signal. (how convenient!)
Happy harvesting!