Hi. They want to know size, origin, age, condition and amounts. Everyone has different ideas about beads so they need info that matches their needs. I am retired now but I once owned bead shops and started bead festivals. People in the bead world have different ideas on whats important so its good to know that many consider the best seed beads to be Japanese followed by Czech and Bavarian mostly because of production standards and techniques such as tempering in the case of glass beads. Beads are like trading cards or anything else, there is a huge learning curve. For instance, India produces absolutely beautiful lamp wound beads that break very easily because they are not tempered since it requires energy and money to make them hard and resilient. However, no one needs to know all of this to sell beads. You just need good photos and the information available. For instance, you say you have 2 to 3 lb bags of matched beads. That's a lot of beads of any size or type. Do you know the size? Seed beads have their own size system but other beads you want to know their dimensions in millimeters. Do you know where they came from? Do you have the original labels? That's what people want to know and they want good closeup photos. A listing might look like this: 2 ounces, 5 mm round, pink, fumed, faceted Chinese crystal beads or maybe 1 lb of Japanese Toho delica size 11/0 frosted grey. If you don't know what they are you can just describe them: Beautiful gold and red lamp wound glass beads 5 x 9 mm bicone with bead release remaining (white powder in the shaft). If you have a whole lot of beads, like many pounds you might want to know some history and terminology because there are also beads made from organic materials, crystals and minerals, metals, plastics, etc.. A photo image search may help you cut to the chase. Hopefully you have some value in your collection. You know there are beads, such as an authentic agate DZI, that can be worth thousands. Also, matched beads generally more value than mixed beads. Good luck.
