Inkscape is great! I have just spent two weeks as a newbie user of Inkscape finishing a design project. I could not be happier with the program: everything I tried to do worked great. Thanks to all the developers and to everyone who has written manuals and tutorials.

I want to export files at the best possible resolution for sharing or viewing,

-- what  save-as format should I select?
-- what options should I select or designate in the second stage dialog window?

Here is what I've tried so far.
For quick views and email, I export a png file (small and adequate).
For high resolution views, I've tried pdf, ps, and eps. In particular I don't know what setting to specify for "Resolution for rasterization (dpi)." Do I want Postscript level 2 or level 3?

I have the same question regarding high resolution printing. In the print dialogue window, I have the option of selection print resolution. Does this vary with the attached printer? I am offered the option of 120 x120, 360 x 360, or 720 x 720 dpi.

Here are my intended purposes:
I print images at home on an inkjet printer (available resolution 600 x 600).
I print on a laser printer (available resolutions 1200 x 1200).
I send print jobs to a printer for posters (unknown resolution but big final output).
I share proofs of my work via pdf.
I incorporate images into LaTeX documents.
I am making an animated film digitally in Inkscape. I save each frame as a pdf, open in Apple Preview, save as a jpg, and then open in movie editing software and edit frame by frame.

I have spent a lot of time looking through the manuals, tutorials, and archives. I have not found the discussion I am looking for in regard to print and output quality and resolution.

I assume that I should set my image dimensions to desired final dimensions. But how do screen pixels ppi relate to print resolution dpi? My monitor (iMac 27 inch display) is approximately 109 ppi.

I'd love to hear the theory behind all these decisions, but if an Inkscape expert just wants to tell me what to do, that'd be great.