I'm trying to set item level permissions from a SharePoint 2010 reusable workflow by passing the list name and item ID as its initial parameters. How I can locate the item by using the init-parameters?
When you create a list, it comes pre-built with un-editable content fields. A unique ID is one such field. So every list item will have it's own associated list ID by default. When you perform a lookup on the item, you can simply lookup the item ID of the current element when using the workflow.
Also, as another note, each list has it's own GUID, that is unique to every list.