Welcome Gigglesforall. Your membership to IAFN will get you the Journal of Forensic Nursing. It is a research based and peer reviewed journal, good for knowing where research in forensic nursing is actually being done. Keep those issues for grad school, you'll find them useful for your own studies.
Virginia Lynch's book is excellent for a broad overview that's up to date. Another to consider is "Forensic Nursing - A Handbook for Practice (Copy right 2006, by Jones & Bartlett Publishers, Inc)." This is the textbook I use where I am a graduate forensic nursing student. Authors are Rita Hammer, Barbara Moynihan, and Elaine Pagliaro.
Also, if you have access to professional search engines, there's a lot to be found on-line in the various profesional journals. The Journal of Psychsocial Nursing, Critical Care Nursing Quarterly, Emergency Medicine Clinics of North America, and many others are where I have found good information. You just need access to a good search engine and time to do the research. Some of the information is outdated, some of it not. But it's good to do the research just to see what's out there.
You might want to contact the grad school you are thinking of and talk to someone in the forensic nursing dept about what they are using. Where I go to school (Quinnipiac University) we also use "The Medical Record as a Forensic Resouce", by Campion Quinn (2005, Jones & Bartlett Publishers, Inc) and a Criminal Law textbook.
One thing to be aware of: This is my fourth semester out of six, and I am only just now doing all forensic nursing lecture and clinical. I also had to take (and buy textbooks for) courses in nursing theories, nursing issues, research and statistics, pathophysiology, health assessment, as well as others. I also found I had to print out many, many assigned readings only available through the internet. Lots of paper and ink expenses. It's best to know about something like that so you can financially expect it.
Good luck, and if you haven't already joined your state chapter, that's also an additional resource for you. Hope this helps.