It's the same principle as with an array but you update the list pointers instead of shifting the array elements.
If you need more specific answers, you need to ask more specific questions. No one here is going to write the sort for your homework assignment, so post the code you have and what questions you have about it.
If the assignment is to implement an insertion sort on a linked list, you need to read your notes on what an insertion sort is. Inserting into a list is not an insertion sort. If that is not the assignment then you need to rephrase the question to clarify what you need to accomplish.