1. Start simple:
The first time you click the add photos button ? and select a gallery, you'll see this:

If you don't see it, no worries. We took you straight to the uploader you used last time. At the bottom of the page you'll see a link to choose another uploader. Click it to see all the different choices we offer.
Now choose the Simple uploader. You'll be asked to click Allow. It's perfectly safe and once you do this you'll probably never have to worry about it again.
Here's a picture of what that message looks like:

We hate telling you this, but if you didn't click Allow when asked, you have to quit your web browser, restart it, and re-select the Simple uploader.
2. Select photos:
Click add files and locate your photos on your computer.
Click on the first image you'd like to add.
Hold down the shift key on your keyboard, and click on another image. All images in between will be selected as well.
Click open.
3. Send them on their way:
Add as many photos as you'd like. Then, just click Upload!
Note: If you're queuing files that are identical to those already in the gallery, you can choose how these will be handled. In the drop-down menu at the bottom you can select whether files with the same name will be added as duplicates, replace identically-named files in the gallery, or skipped.