To casual photographers, I recommend Google Photos for organizing your digital photos. I find its shared album feature, which was introduced late last year, particularly useful. This comes in real handy when, say, you participate in an event with some other folks and want to collect all the photos — and videos too — taken by them into one place later on.
All you need is a Google account, and it is likely that you already have one. If you use an Android device because it demands you have one, or if you use Gmail at all, in which case your Gmail address is your Google account name. Google Photos is supported cross-platform. You can access its website on a standard web browser, with which you can upload photos from any device—your digital cameras, CDs/DVDs/BDs, USB memory sticks… you name it. They also provide mobile apps for the Android platform and the iOS platform.
You can upload unlimited number of photos as long as you let Google downgrade the quality of your photos in the process. “Downgrading” might sound bad, but the difference may not be all that visibly noticeable. I believe this option works well for most of the casual photographers. Confusingly, they call that “high quality” uploading option. See “Choose a storage size – Google Photos Help” for more on this.
Alternatively, you can choose the “original” option, in which case your photos will be uploaded as is in their full gory with no degradation. The catch is that their file size will be counted against your pre-allocated storage space by Google, which I think is 15GB. So if you are a real shutterbug with a high-end digital SLR and shoot photos in the RAW format… perhaps Google Photos is not for you. That’s why I specifically said “for casual photographers” at the very top.
Personally I recommend installing the Google Photos mobile app on your smart phone if you are taking photos with it. You can have all the photos you take with your phone automatically uploaded to the Google Photos server. So even if your smart phone gets broken along with the storage unit, your photos are safely kept on Google Photos.
In addition, what I like about this setup is that you can have two-way syncing. After your photos are uploaded, you can browse the photos on your PC (using your web browser) and/or tablet (using your web browser or the mobile app), which has a much bigger screen than your smartphone’s and makes your photo organizing so much easier. When you delete any of the photos there, you can have the original photos on your smartphone be automatically deleted too. I think that is much more convenient in removing useless photos than trying to do it on your smartphone.
By the way, if you turn on the automatic uploading feature in your mobile app, your videos will be automatically uploaded too, which is totally fine with me. From my limited experience, though, the resulting quality is better if you upload them to YouTube.