What is the correct way to share and be able to edit files from a hotmail account (default for the WP7 phone) and a live account I can sign into from a computer. I shared the folder from live account which sent the email to the phone, which downloaded the files. When I edit them on the phone and save them, the changes don't seem to upload to skydrive (not visible from the hotmail account).

I downloaded the skydrive app and that doesn't seem to work either. You can see the spreadsheet but the changes don't seem to make it back to skydrive from the phone.