Username Search

[gharpe2]

How do I conduct a search for unique usernames and get a count of how many people are logged on at any given time?

[piebob]

for the unique usernames, you could search for usernames and then pipe to the 'uniq' command:
http://www.splunk.com/base/Documentation/latest/SearchReference/Uniq

for the count of users logged in, you can use the stats command with the count function:

http://www.splunk.com/base/Documentation/latest/SearchReference/Stats

and

http://www.splunk.com/base/Documentation/latest/SearchReference/CommonStatsFunctions

you might find the Splunk tutorial helpful in general:
http://www.splunk.com/base/Documentation/latest/User/WelcometotheSplunktutorial