What sort of information? Everything specific to the engine itself is in the Owner manual, but things like fuel filters, coolant and such are not part of that because those are supplied by the chassis manufacturer that installs the engine. If you don't have an owner manual for your year ISL, you can get one from Cummins or view it online if you join the Cummins Quickserve web site;
Your chassis manufacturer probably has a summary of the overall maintenance needs too. Both Freightliner and Spartan have this info on their web sites.