1. Store them in a box, properly organized, away from direct sunlight. Temperature controlled rooms are also a plus given high heat/humidity can damage books if stored improperly.
2. Google suppliers in your immediate area. Some might be willing to do a pull list for you.
3. Variants rarely are worth anything compared to original covers. Buy those only if you like the art.
With that out of the way, does anyone own any significant floppies/key issues worth sharing? I just got pic related this past week.