Hello, I'm new. LOTS of ???

Hi, my name is John, and I have roleplayed for 16+ years (gad!).

I think TSR must be doing something right if it came up with
Spelljammer.

To the questions and problems.

While TSR does a hell of a background, the system is a little clunky.
As such, I usually play GURPS.  I also am interested in Castle
Falkenstein.  I am attempting to set up a crossover type of campaign for
some gamers.  Problems is that I have only played Spelljammer (under
duress initially, but I quickly loved it) once, and I only bought the
"Legend of the Spelljammer" on a whim at Kay Bee hobbies for 4.99 (yes,
that is my hot tip, see if you can find it!)

Problem 1
I need to know which book to try to brief me enough of the background to
make the conversion.  Adventures in Space, the Warcaptains handbook,
whatever?  Suggestions are much appreciated. If you know where I can
also find this book on the cheap, I will name my 10th child after you
(no I am working on number one)

Problem 2
If anyone could synopsis the difference between major and minor helms
for me, what they do and WHY DOES A SPACE SHIP HAVE SAILS!?!?!, I would
appreciate it.   I know this is what the book will tell me, but I am
impatient and I figure you folks already have covered all the
inconsistancies and ironed out the difficulties in a professional
manner.  It would also help to know why all these ships look like fish
or bugs or what not. Please you wonderful people you (obequiese am I
not?)

That's all for now.  I have to try to convert an Illithid to a GURPS
format without a polymorh spell.  Wish me luck!