There seems to be a lot of interest in this, so I'll start posting the links I have. I'm afraid it's going to be a little piecemeal, as they're scattered across my hard drive and an immunology test is coming up fast. So to start, I'll post a few anatomy links that I've found helpful, and will try to add subjects as time permits. Maybe we can start a new thread for this? I imagine others have many more and probably better links...perhaps it's sticky-worthy if we get enough, since I think there have been threads with links before, but they're tough to find. Anyway: anatomy/hist!
WEBMD ANATOMY: all sorts of nice pictures, defs, etc.
http://www.mythos.com/webmd/Search.aspx
LUMEN HISTOLOGY: Absolutely essential.
http://www.meddean.luc.edu/lumen/MedEd/Histo/frames/histo_frames.html
UW HISTOLOGY: Not as awesome as Loyola's, but still helpful.
http://www.anatomy.uiowa.edu/genhisto/GHWIN/index.html
UW DISSECTION VIDEOS: My all-time favorite. I owe a few anatomy practical aces almost exclusively to Rohen and this. I'd highly recommend watching the relevant video before and after a dissection--you'll be a lab deity, since you'll have basically already gone through the dissection.
http://www.anatomy.wisc.edu/courses/gross/index.html
MUSCLE LIST: A nice but simple one, with some exercises associated.
http://www.exrx.net/Lists/Directory.html
ANATOMY TABLES: Lots of useful anatomy tables by both system and region
http://anatomy.uams.edu/htmlpages/anatomyhtml/medcharts.html
MUSCLE ATLAS: Another nice muscle atlas, with all the essential origins, insertions, arteries, etc. Great for quizzing yourself or quick reference.
http://www.rad.washington.edu/atlas2/
ANATOMY TUTORIALS: A little simplistic, but these helped me to get a good general overview. A good way to start out with things for a quick overview.
http://anatome.ncl.ac.uk/tutorials/index.html
DISSECTOR TUTORIAL: Nice for knowing what's going on. Very well done, with x-rays, diagrams, etc.
http://www.med.umich.edu/lrc/coursepages/M1/anatomy/html/courseinfo/labs_regional.html
Phew. All I've got for now. Some of the links I wanted to provide no longer work, and the same could of course be true about any of these by the time you start. If they last, though, they'll be helpful.
Someone asked what books and materials I'd recommend. I was fine with Moore&Dalley for text, Netter and Rohen for atlases, and Netter flashcards (VERY helpful, those). Others will certainly have good additions to the list. I found the internet resources a huge help, though, as a lot less time is spent flipping.
Best of luck!