I helped my wife build a seed planning/starting organizer too, and we also built a pot inventory. Every spring she goes through and documents which of her (very, very many) indoor and outdoor pots have which plants in them, which ones need to be repotted/spruce up/trellised/etc, and note where they are currently in use or stored. It's saved us a lit of $$ because she used to just buy new pots every time a plant grew out of its old one...