[Shotimes] AC questions

[van Oss]

I have a set of R134 manifold guages and a can tapper.  I would like to get 
up to speed so I can do my own AC work as much as possible.

1. Do you know any good books or websites where I could learn more about AC 
procedures?

2. Good websites for buying AC parts and tools?

3. Best source for a vacuum pump?

4. I am contemplating converting a 92 Sable with 155K.  This is another car 
to be donated to my sister-in-law with the autistic twins.  She has asthma 
and needs AC.  I need to keep the cost down!  R134 retrofit kits sell for 
$55 to $90.  That's within my means.  Are these kits any good?  Car's got 
maybe a couple of years left so it doesn't justify gold-plated AC.

Thanks.
VO