Open Automator and create a new Service. Set the Service to receive selected text in any application from the drop down menus.
Drag Copy to Clipboard from the Utilities library into the workflow. Drag Run AppleScript from the Utilities library into the workflow.
Paste the below text in place of (* Your script goes here *):
tell application "Notes" to activate tell application "System Events" click menu item "Notes" of ((process "Notes")'s (menu bar 1)'s ¬ (menu bar item "Window")'s (menu "Window")) click menu item "New Note" of ((process "Notes")'s (menu bar 1)'s ¬ (menu bar item "File")'s (menu "File")) keystroke "v" using {command down} end tell
[crarko adds: I compiled the script and it seemed to work. I didn't test the Automator Service.]