How to link to a SharePoint site:
This is fairly straightforward. This is the URL structure. You can get the one for your workplace's address by looking at it via

How to link to a One Drive business site:
This is slightly trickier thanks to Microsoft's confusing branding strategy. If you use the default OneDrive (nee SkyDrive) preset in GoodReader you will be taken to the OneDrive personal account. The OneDrive business is actually a SharePoint directory, therefore you have to use your SharePoint URL to connect to One Drive

Where it says “Your Workplace Email” above:
If you worked at, it would be you_job_com. Instead of using the dots as in “.” between each part of the URL, you use the underscore “_” character.