This is an post taken from our old website.  It was originally posted in 2013 to help with an issue which many people were having with Magento CE at the time.  We have deprecated our other old blog posts but have decided to keep this one as we believe it is still useful to some… (please note that this was written alongside Magento CE 1.7 but I believe it still works up to the 1.9 release)

So, we have been tinkering with Magento CE lately and hit a stumbling block when it came to making somewhere in the region of 16,000 product images display on the frontend. The solution didn’t present itself clearly for quite some time, so here goes the basic guide for all those store builders who have more images than they can individually upload via the backend…
Assuming that your products are already listed without images:
Upload your images to media/import. If you do not already have a folder named “import” within your “media” folder, just create one.
Log into the admin area of Magento.
Click System > Import/Export > Dataflow – Profiles
Click Add New Profile
This is the screen you’ll be presented with (Click on the image for a larger version):

Make sure the “Enclose Values In” field is blank. Under the heading “Field Mapping”, enter the image categories you require, this example is very basic, but you get idea. You can add categories such as image labels, the choices appear in the dropdown menus each time you add a new item. Be sure to include “sku” as Magento uses this value as the product’s unique identifier.
Save your new configuration.
Create a new CSV file in your normal editor such as Excel for example. Create columns for each of the fields you created in Dataflow. (sku, image, thumbnail etc). List your sku numbers in the appropriate column (copy and paste from the original stock list works well here) and input your image titles. Be sure that the image names begin with / as in “/web-design.jpg”
When all details are complete, save your CSV and return to Magento. Within the Dataflow profile you have created, click “Upload File” then select the new file and click “Save and Continue Edit”.
Finally, click the tab “Run Profile”. Select the file you have uploaded from the dropdown menu and click “Run Profile in Popup”. Magento should do the rest for you.
Alternatively, if this basic guide is still beyond you, give your web designer a shout, we’re always happy to help….

Well, hopefully the oldies are still the goodies.  Magento is such a powerful, fantastic e-commerce platform, as well as a complex mind-boggling beast at times!