In my never ending quest for information related to hand sewing, I stumbled upon the most wonderful website dedicated to hand sewing techniques of eras past, www.vintagesewing.info/index.html.
Vintage Sewing Library Reference, Inc. has electronically compiled various books and training manuals dating as far back as 1893 and some as recent as 1957. One can click on various categories, i.e., dressmaking, millinery, tailoring, etc. Or, instead of a category, you may want to choose an era. For me, I'm all about the pre-1900's. The manual (cir. 1893) provided in this link has been found to be an invaluable source. Along with sewing instructions comes the corresponding diagram (don't worry if it looks small, just click on the diagram and the site will enlarge it for you!).
I don't know how to use a sewing machine and, I figure, since hands were made before machines, that I should be able to get along just fine without one for some time. After all, the very premise of haute couture was built on hand sewing. I know some are put off by the very thought of casting their trusted machine aside, even for a moment, but I've found hand sewing to be most therapeutic. I'm also getting smarter with garment construction as I go along. I find I'm not so quick to stitch an item together without first checking to be sure I have the right, or perhaps the wrong, sides together. Also, I find my brain working in ways that amaze me. I'm getting better at problem solving. And get this, I actually like it! My former math teachers would be proud!
All in all, whether you craft by hand, machine, or both check this site out. The more you know, the further you'll go.