So that's, um, how you do it

I've said it before - I rarely sew for myself.  But I'd like to, I really would.  I see the things Melissa and Julie make and adore them.  I have the patterns, I have plenty of fabric, but I also have fear.  I am not scared of the actual sewing part.  It's the fitting part that stops me cold.

So I am setting out to conquer the unknown.  I actually signed up for a sewing class and we are making a lined jacket.  Yes, you got it right, a lined jacket (I am doing version B with version A pockets).  My first class was on Monday night.  I showed up with my pattern and three yards of muslin.  After being properly measured, I started cutting the muslin using the pattern unaltered.  When it was all sewn up, it was obvious that I needed to add some length (about 3 inches!) and make a bust adjustment.  I get the length thing, but how in the hell you do make a bust adjustment?  I just sat back and watched as my instructor got out her ruler and marker and started drawing lines and then cutting.  Here is what we ended up with...

I completely understood what she did, or at least that is what I thought.  When I took the pattern out today to lengthen it at the waist and adjust the other pattern pieces accordingly, this one was all messed up.  I spent a good half hour trying to put it back together, but, like Humpty Dumpty, I am missing some pieces.

Anyone have any advice?  Books I should look at?  Helpful little websites I should peruse?  Maybe I should just wait until Monday and start over again....