You would send the 1040 and all supporting forms and schedules. For example for a 1040, you will find a number in the upper right hand corner of the forms. The is the sequence number that directs the order of attachement. You will also need to attach W-2, 1099-R and any form with withholding. IL may request a copy of your Federal return. It will tell you so on the IL form.
If it is a worksheet, it will indicate that it is just for your records.
