Hi all - I'm a complete newbie, but I created my image and need it to have a transparent background.  Is there a way to do this with Inkscape?

Hi,

Follow the below two steps 

• Open File → Go to "Document Properties" and click the background color. Make sure the alpha channel is 0. 
• Go to File → Export Bitmap (Shift+Ctrl+E) and save a file with a .png extension.

Ok - got it.  Thanks.  Now... I originally outlined each "rock" in white to make them look separate.  But I would like that white outline to show whatever background the image is on (black in this example).  How do I fix this?