Crystal welcome to the forums!
I know your question sounds like a simple one, and actually it is; unfortunately the answer isn't so simple. There are so many different ways to connect, save and publish to Server that it took Jonathan Drummey a 2,346 word blog to describe and explain all the ins & outs. With lots of wrinkles included. So rather than give you the quick answer that may or may not match your situation, I'm going to just post a link to his blog and hope you read it thoroughly and find Update/Refresh Joy.
Did you count each word individually??
Shawn really really likes your work Jonathan! I'm enjoying it myself and hope that it will solve my issue after I look it over tomorrow.
HA! Didn't read it that closely.
I've been messing around with the instructions that you wrote up. I'm still not able to add new data to the spreadsheet and have it update automatically to server. My guess is the Tableau Server doesn't have the right permissions to the folder that holds the spreadsheet. I have the folder open to everyone but it still is not working. I'm going to talk to our Network Admin about the permissions issue.
Until that gets fixed, I'm stuck at still having to republish from Desktop to Server.
Thanks for all your wisdom,