If you think of an analog desk (the kind with real drawers and a chair), the best workflow happens when you can keep the desktop clear to use as a workspace for whatever project you are busy with. The same goes for your computer.
The great thing about your Mac is that it is already set up with an organizational system in tact. If you look in your Home folder (the house with your account name on it in the finder window, click on a neutral area of the desktop and click Command-N to bring up a new finder window), you will see folders to keep your documents, movies, music and pictures. In each of these places, you can make as many folders as you like to organize your stuff.
Or, you can make a catch all folder called something like, oh I don't know, Catch All, or Stuff, or My Stuff, or Pinky's Plan for World Domination. The point is, keep your desktop clear of clutter. It will make your computer run smoother.
If you want to access your documents or applications, drag them to the right side of the dock (to the right of the dotted line). This makes an alias of them, and when you click on the dock alias, the display is lovely. Sometimes when it's raining outside, or I am grumpy (since I'm always on a friggin'diet), I click on the Application folder which I have put in the dock just to see the pretty colors. Look!
If that doesn't work, I go to Kitten Break:
And if THAT doesn't work...