I am just getting started with a sewing machine and have a few beginner questions.  I decided to try the stuffsack kit, but before using the spintex fabric I am practicing on some cheap rip stop I got from the local fabric store.  I am using the plans that came with the kit and are posted in the workshop section of this site.

Here are my first set of questions (I am sure I will have more in the future)... 

1) Do you start the seam with the sewing needle just off the edge of the fabric, or directly on the fabric? 
2) Does every seam get a forward and backward stitch at the beginning and ending of the seam?  And, does this all stay on the fabric, or do you run it off the edge?
3) When creating the first seam on the stuffsack where you join the two sides together after folding the large piece of fabric, do you run a complete seam from one edge to the other on each side independently, or do you run one long seam and pivot at the corner?
4) Should I be doing a felled or french seam for the stuffsack, or is a simple seam adequate?
5) What are the main benefits of the felled vs. french vs. simple??

Any help is greatly appreciated!  I got a book on sewing, but it really doesn’t cover this stuff that I can find.

Thanks,
—Matt

1) in the fabric
2) Yes, in the fabric
3) either one is fine.  Sharp corners are easy if you leave the needle down in the fabric, then raise the pressure foot and pivot the project around the needle.
4) simple is fine for sil stuff sacks and is easy & quick.  If you want to experiment with different things, go ahead.  There isn’t much you can do that will render your stuff sack unusable.
5) felled & french seams protect the raw fabric edge, simple seam doesn’t.

Thanks Ayce!

Are the French and Felled seams stronger or easier to seam seal? 

—Matt

No.  But tarps use a single felled seam in slippery sil, so if you plan on making a tarp in the future it would be useful to practice it on the first stuff sack seam (ie the side seam, not the bottom seams).