I just signed up on this forum and it looks like a great resource for using inkscape. I'm looking forward to a lot of fun with this program.

For now I need to know how to create a text only png with white lettering for use on a colored or black T-shirt. As I understand it the background in Inkscape is already transparent which is what I need. So my question is, how do I change the background to something other than the default white while I'm making my logo with white text so that I can see the lettering? Thanks in advance.

in file>document properties you can change the background color by clicking on the swatch top right, just remember to change it back before exporting or final save!

Thank you very much. That was just what I needed. Much appreciated.

please ignore, somehow I posted twice. can't figure out how to delete this post.

Another method is use a color (such as black) to design your text, then when ready to export, change it back to white. It's so fast to do, even with lots of text (the tip is to put your white text on a separate layer from the rest of your objects), then click on select all objects in layers, then change the fill back to white, it's so quick to do. You could alternatively just change the stroke (to say black) instead of changing the fill, that would give you a better feel of the end product.
Some people actually create the usual look of the checkered background, and change it in inskcape to be their default background, that's a little more complicated, but can be done (you can search the topics to find out how to do it if interested).