To my knowledge, there is no Samsung, Google, or Android phone manager like there was for Blackberry.
If you want to transfer or sync media to your device, give DoubleTwist a try. It's very similar to iTunes, but it was made for Android devices.
For transferring data like documents or other misc files, I like to access my phone SD card as a mass storage device manually in my computer. I do that because most of those files are important to me, and doing it manually gives me a warm and fuzzy feeling that they are exactly where I put them.
To transfer files from the phone to my computer, I just push them using the Bluetooth transfer (long press on file, share using Bluetooth). Simple and effective. Other stuff I've tried has been too complicated.
I just use a robocopy command to copy files. I save them to a notepad so I don't have to type it all out each time. Simple and effective, but not automated.