Where can I find information on how injuries affect the body?

I'm a writer, and I'm looking for information on how injuries affect the body. For example, I'd like to accurately portray what happens if someone dies when hit over the head with a blunt object. Is there an online guide that helps writers with problems like this? I know about the book Body Trauma, but I'd like to find a free guide before I buy anything.Where can I find information on how injuries affect the body?i don't think things like this are available as free guides anywhere, medical texts (for a price or in a library) may describe different trauma presentations, these are likely to be in medical terms and not simple layman english, good luck