How to retrieve the List GUID and List URL in a Sharepoint 2010 workflow without hardcoding it?

I am making a sharepoint 2010 workflow that generates a link to a ics file so that it can create an outlook appointment, but the problem is I need to pass the list path and GUID in the string builder to create the link. I don't want to hardcode those values in (and I don't want to create a column and put those values in), how can I access those values in the workflow?

Thanks