How to add data to Sharepoint site (form) programmatically (automated data entry)

Hello,

Let me start by saying that I do not have too much experience with Sharepoint. We have an in house Sharepoint site (form) that users can go and enter data (less than 10 fields including text boxes and drop down lists) and run some reports on that data. All is good with this part, but I was asked to come up with a way to add data in an automated way to the site. This will only be done under certain scenarios. Most of the data entry will be done by users going to the site.

My question, is it possible to add data to a sharepoint site programmatically (c#)? If so, how do I accomplish this? Do I add data directly to the SQL server DB? Do I use the Microsoft.Sharepoint.Client?

Any examples around?

Thanks