Upload & Sell: Off
If you use DNG files the processing edits, metadata, star rating and lables will be saved in the file, so if you open the file in another Lightroom catalog or in Bridge/Photoshop you will be able to see them.
Not sure about process steps, and stuff that is Lightroom specific, light the Pick, Reject, stacks etc won't go with the file as they are stored in the Catalog.
Once idea that was written in Martin Evening's book on Lightroom (well work getting), is import the images to computer A, do some work, then export those photos as a Catalog, including the original files. Put this new catalog on computer B, work away, but now when you want to move between computers you don't have to export/import all the original files again, you can specify that you just want edits and new files (if you created a few PSD/TIFFs via Photoshop). You can import this new catalog into your existing main catalog.