After completing the process here are my own answers:
- It turns out the GoDaddy support representative was wrong when advising me to use a driver signing certificate. I needed a code signing certificate.
- The certificate does not show the details of the contact person (which are included in the certificate signing request). You can see the certificate details before you submit the request (I missed it initially). In my case the details shown are the company name, city, state and country.
- The documentation requirements depend on the company requesting the certificate (in some cases they may not need any documents at all). GoDaddy has very friendly support, so you should can the requirements from them. The process can take a few days to complete (but they may be able to help in doing it faster).
- When using Internet Explorer both for the certificate request phase and installation phase, the process is seamless. I believe it uses Microsoft's Certificate Enrollment API (which is also described in this MSDN blog post)
- As mentioned by JP Alioto, the process for using the certificate is described in the article "Signing an app package (Windows Store apps)". To use the new certificate in a specific project:
- Open the projects .appxmanifest file
- Go to the "Packaging" tab
- Next to the publisher field, click "Choose Certificate"
- In the dialog that pops up click "Configure Certificate" and select the drop down option "Pick from certificate store ..". The certificate should be available as one of the options.
- To export a certificate, you can use the following process:
- Run certmgr.msc
- Locate the certificate
- Right-click > All Tasks > Export to launch the certificate export wizard, which has an option to export the private key
- Warning: the private key is supposed to be personal and you should protect it. It is probably OK if you copy it to another machine that you control (assuming nobody can snatch it in transit). Sharing it with someone else may be risky. I was not able to find information about how exactly the private key is used by Windows, but it may be a bad idea to have several people share a private key.
- To import the certificate and private key from a PFX file, right click on the file in Windows Explorer, and elect "Install PFX". This will launch a straight-forward "Certificate Import Wizard".