For anyone that needs a "point in the right direction", here is what I found..
I didn't realize that I didn't have to use a csv file to upload the data. I can add points directly from my SQL Server DB by using the REST API.
While I was at the developer's area looking for a Python script I found that they support .NET, so I downloaded and installed the API. You are looking for the ArcGIS Runtime SDK for .NET Visual Studio Extension.
Next I opened Visual Studio and created this tutorial:
Add a layer from an item | ArcGIS for Developers
You will learn how to build an app that loads and displays a layer from ArcGIS Online.
It didn't seem relevant at the time but I thought it would demonstrate the API.
It first asked me to do another tutorial first to create a feature layer (my points): - This was an important step because it seems like you must first create the layer in ArcGIS Online before doing any sort of edits with the API. I could be wrong about this, as I remember seeing var layer = new FeatureLayer()
Create a new dataset | ArcGIS for Developers
With the last tutorial I was able to display a map in Visual Studio, excellent!
Next was looking to see if I could add a point outside of ArcGIS online.
Before you can access the layer if it is not public, you must have an access token. Here's how to get one using Postman:
Get an access token | ArcGIS for Developers
By the way, Postman gives you the C# code too, so you may add this to your REST Client.
Next was the tutorial I was waiting for:
Add, edit, and remove features - (this was a huge leap forward) I had no idea I was looking for a feature Layer.
Add, edit, and remove features | ArcGIS for Developers
Add, edit, and remove features from ArcGIS Feature Services.
Documentation: Features and Geometries | ArcGIS for Developers
This tutorial teaches you how to add a point to al layer, edit it and delete it. Note that this layer is viewable in both the ArcGIS online version and the Visual Studio API version.
I'm currently working on making more then one add/edit/delete in a single call:
Apply Edits (Feature Service/Layer)—ArcGIS REST API: Services Directory | ArcGIS for Developers
This operation adds, updates, and deletes features to the associated feature layer or table in a single call (POST only).
The applyEdits operation is performed on a feature service layer resource.
I will try and keep this thread updated, and thank you all again for all your help.
~G