In terms of online resources (not just for anatomy but for all kinds of drawing related topics) I would highly recommend the online videos of Stan Prokopenko (www.proko.com). He's a very skilled artist and educator and his videos are concise, well produced and enjoyable to watch. Some of the content is 'paid for' but a fair bit, including the "landmarks of the human body" video, are free.
The classic text on artistic anatomy is by Dr Paul Richer. It is probably the best reference book of its kind. It's very detailed, with excellent diagrams. I believe a pdf version is available too.
For a much shorter reference book (say, to keep by your easel during figure drawing) - it's worth having a look at James Dunlop's Anatomical Diagrams for Art Students.
A recent acquisition is the Complete Guide to Life Drawing by Gottfried Bammes, which has some slightly strange illustrations from exercises set by Bammes to his students. In amongst these, though, are some really excellent schematised diagrams of major features of the body. These diagrams are especially helpful in breaking down the more complicated areas of the body in order to better understand their structure. The one on the structure of the pelvis, for example, is useful - and I've copied it a number of times.
Also worth a look is the L'Ecorche app which I highlighted in my last post.