@caretaker if you go to the Medtronic diabetes website under the Support section there is a link to all the different infusion sets with short films about each type and how to insert them as well as Troubleshooting.
Are you having a specific problem with the type you are using? There is a choice of QuickSet, mio, Silhouette and Sure T so if you don't get on well with one type ring Medtronic or ask your DSN to try a different set. The Sure T are stainless steel whereas all the others are soft cannulas.