Here is how you can add data into your Maps site:

1. Open the LAYER ADMIN. This will display a list of all the layers in your map site.
2. Click the "NEW LAYER" button at the bottom of the screen. 
3. Choose between uploading a new layer, uploading a WMS layer, and creating a layer using an existing data source. I want to add an entirely new layer so I will click "Upload new layer".
4. Click "Upload a file" to browse your computer for the file. Here is a sample file you can download and use to try uploading a layer: Water Mains You can also drag and drop a file into the "Upload a file" green button area.
5. You can change the filename of your layer if desired.
6. Once you have selected the file for upload, click "Save".

If you are loading a really large dataset, Lightship will email you when the data has finished loading.  

Once your layer is visible in the Layer Admin, it is ready to be added to any map. From here you can also edit the layer including the name, style, scale dependency and more.