Most suspension books deal with suspension geometry and not the fabrication of the various linkage bits. Have a look at Carroll Smith's "Engineer to Win" and to a lessor degree, "Prepare to Win", also have a look at Fournier's "Metal Fabricator's Handbook."
Then get a digital camera and a noteboook and go to many races. Take detail pics of the suspensions of vehicles like yours that are consistant winners or of exceptional fab quality. Note what it is that you like or dislike about the design (index your notes to the pics) and talk to the folks working on it. See if there are issues or things they'd like to change about how the parts were built and note those comments as well.
Welding fixture construction is a volume by itself. Sometimes some pieces of plywood nailed together is all you need, other times (much rarer) you'll have 10x fab time in the fixture as you do in the part. Look for a real text on welding. Finch's "Perfromance Welding" is not what you want. Try the bookstore of a JC that has an extensive welding program.
"Teach you all I know and you're still stupid"
-- Howdy Lee
My bet is that you will find many books that discuss different suspension designs from a conceptual level. They may even point out some of the benefits and drawbacks of different designs. But, most books will be written from the perspective of road racing cars, circle track cars, or maybe dirt track cars. I don't know of any that even attempt to correlate that information to a long travel off-road suspension designs.
As for the various designs of a-arms, the possible designs are limited only by your imagination and the configuration of your vehicle. There is no right or wrong design. There are however, conceptual designs that work well and have been modified to fit hundreds of different vehicles. As for the jigs needed to construct repeatable results, the key is to fix the location of all key points on the jig such that they are accurately located and positioned for your design. The jig itself can be made very simple or very complex depending on your needs and what you have to work with.
I guess I am assuming that you already understand suspension geometry and you have your design parameters clearly defined. If not, you should start there because the design of the a-arms won't mean much if the suspension doesn't work. If you need an exact blueprint for all of your a-arms and their jigs, the steering will probably be the next thing you will need help with. Maybe you should consider paying a qualified fab shop to do the work for you. See the linkz section or the banner ads at the top.
"The only source of knowledge is experience." - Albert Einstein
This isn't going to be a race truck or anything. I got turned onto off-road go karts and been researching on the web, but most places "sell" the plans and I've seen some setups that I like and I figure this might be a good learning experience. I've only ran into two sites that have any info of a-arm fabrication so I've gotten a little knowledge, but with what I'm thinking of doing, I'd like to go into deep research on building a-arms and how to get the most out of a set.