I found this cool site that has some basic hand stitching techniques in a video tutorial format. I thought they would be good to know for field repairs of gear.

You can find an index of stitches here. A lot of the video are geared toward embroidery, but there are some other useful videos also.

Back Stitch - This stitch is supposed to be the strongest of the hand stitches and would probably be the most common stitch used in gear repair.

Running Stitch - Another useful basic stitch. You should add a back stitch after evry few running stitches to help lock the stich

Button Hole Stitch - Stitch for making button holes.

Herringbone Stitch
- Basically a zig zag stitch for hand stitching. There is also the Double Herringbone that creates a "XXXXXX" pattern.

Here's another site that talks about hand stitching that you may want to check out.