Take your time.
My point in bringing up Jasher is ... why was it excluded? For what reason? Don't just focus on the single book. There were many books, of equal footing with those included, that were purposefully excluded. It would be just as valuable to look at "The Shepherd of Hermas" (
http://www.earlychristianwritings.com/text/shepherd-lightfoot.html).
And you might want to add this to your list of reading material if you find some spare time:
http://en.wikipedia.org/wiki/Ten_Commandments#Exodus_20.2FDeuteronomy_5 make a copy of Commandment 2 in notepad.
and compare comandment 2 to the one here:
http://www.topmarks.co.uk/judaism/commandments/tencomms.htm copy it too to notepad.
and compare with this source:
http://iknowrecambridgema.tripod.com/TenCommandments.html and copy it too.
and compare with this source:
http://www.whitestonejournal.com/tencommandments and copy it too.
and compare with this source:
http://judaism.about.com/cs/judaismbasics/f/tencommands.htm and copy it too.
and compare them all with this source:
http://www.levitt.com/hebrew/commandments.html#c2 Do you begin to see a pattern here?
What were you taught?
And another link for your reading pleasure:
http://www.positiveatheism.org/crt/whichcom.pdf As I've asked here many times before. How can you believe anything so complex it takes many hundreds of pages when they can't even keep honest 10 simple declarative sentences written in stone?
