I am in need of a couple good resources to learn about mixed connective tissue disease, i am studying for myself and writing about it for class?

Would highly recommend going to any or all of the following online sites: Mayo Clinic, Johns Hopkins School of Medicine, Cleveland Clinic. More specific data can be sourced at National Library of Medicine and PubMed.

Any recent, updated rheumatology textbook should be fine. For online information, most available information is for patients and/or their relatives, UptoDate would be reliable, paid subscription.