There's only a couple of things you should need.
1. Set the file location for ripped media. When that is done, it should store the data where you want it. It's normal and a good practice to store it as Artist\Album.
2. To change location of you media you only have to use the "Rename, Move & Copy Files" tool. It's under right click and Library Tools. Select a few files first and use this tool. Make sure you select the "Update database to point to new location" option from the drop down list. That enables you to update the location of the files, without actually moving them. Prior to this, you should move the files from C: to D:
Then you use the "Find & Replace" option. Find C:\ and Replace: D:\ as one example. Check the Preview window to make sure it's destination is correct.
It would also be good to check the path for the Cover art. You should probably use the D drive for that as well. I would recommend creating one folder for Music, Video, Images, and then sub directories for media sub types. That way you have to power to create a good set of automatic import rules later on.