How you store thousands of photos is partly up to how you prefer to organize them and if you want to preserve them. If you're going to keep the photos in good shape well into the future, look for archival-quality photo storage boxes. You will likely need multiple for such a high quantity of photos.  We'd also recommend finding a logical way to organize and categorize your photos, such as chronologically. If you want to get really serious, keeping a notecard (that is also archival) with information about the photograph is also a good idea. That way, future generations–or even yourself when reminiscing–can have more details about each image. A separate notecard is important because writing on the back of a print can damage it over time, especially if you use pen.