Well, I did it and I too am mechanically inclined but had never done one before either. Besides a bit of a hiccup with the front pump not working properly, (Not built to the manuals specs by a local Aamco trans guy..it was a free donation so I tried it), the trans build was pretty straight forward and is AMAZING. The detailed descriptions he gives along with the pics makes it pretty easy to follow along. If you are going to dual feed the directs, I found the instructions a bit less than clear, as is isn't spelled out what should be done, unlike the rest of the manual. Do a search on this board or just ask Chris to clarify what steps need to be done.
The hardest part I found during the build was to drop in the forward/direct drum assembly past the band. The direct drum wanted to get hung up on the band, and since I didn't have the special tool which hold the forward drum inside the direct drum, when holding it just with your fingers, it gets heavy really fast! Anyway, I cut a whole bunch of little metal strips from some sheet metal which I placed all around the inside of the band to "shoehorn" the direct drum in place thereby protecting the band from damage.
I had bought, from ebay for twenty dollars, a
low/rev housing remover/installer tool. This tool made life a lot easier when removing and installing this piece. I recoomend you get one. As well, once you are finished the build you will need a
transmission pressure guage to make sure eveything is what it should be and avoid the mistake I made assuming the pump was working correctly. Make sure you have a nice big bench to work on..it will make life a lot simpler. I provided links to the pieces I bought.
If you have on of CK's rebuild kits, you will pretty much have eveything you need. I didn't and had a TCI kit which I had bought years ago in anticipation of this buildup. I had to order a washer kit from CK as well as a teflon ring kit and a servo 'extendo' pin.
My advice is to just dive in. It really isn't as bad as it looks once you get in there. Like I said, I had no previous experience whatsoever, and even though it has only been a month, this tranny is living under constant abuse from my 455 Pontiac engine with 500 HP and 600 Ft lbs torque in my 3800 Lb 1980 Firebird.