Is there any current documentation on how to add network nodes to Splunk to gather data?

I recently started a new job and used Splunk at my old one. I know the power of Splunk and know it will be useful for my new job. We have downloaded the free version to see how much data we are processing to determine which version of Splunk we will need, I just am having a hard time getting it setup. Is there any current documentation or videos on how to add your network nodes to Splunk to gather data? A lot of what I am seeing is 5+ years outdated.