1. Add your photos/images to your Photos folder in your Dropbox (on your desktop).
2. You can organize multiple galleries by creating subfolders, or albums, within the Photos folder. You can do this by right-clicking inside the Photos folder and selecting New.... > Folder.
3. Right-click on the new or existing folder and choose Dropbox > Share link. This will copy a link to this folder to your computer's clipboard.
4. You can now send this link to other's via e-mail, messaging programs, etc. to invite them to share these photos. Do so by pasting the link (right-click and select paste or CTRL-V).
Photo Sharing from the Dropbox Website
1. Sign in to the Dropbox website (if you haven't already done so).
2. Click on the icon next to the Photos folder or any subfolder to select it.
3. Click Share link from the blue action bar that appears at the top of the file folder.
4. You can select Copy Link to This Page and then paste the link into an e-mail to share the photo folder with others. Alternatively, you can insert e-mail addresses into the pop-up window and invite others to share this photo folder directly through Dropbox.