Okay after much research over the past couple of months here is what I have gathered so far.  Please let me know if I am off on anything or missing something.

There are three types of build and of those three there are three methods to build:

- 100% complete FFL paperwork required (most recently front trunion holes not drilled for adjustment)
- - - - - - - -  Already heat treated, top rails bent, lower rails attached
- - - - - - - - Global Trades seems to be the preferred manufacture
- Pre-Bent
- - - - - - - - Needs heat treated
- - - - - - - - Needs all holes drilled
- - - - - - - - Needs lower rails attached via (in order of preference) spot weld, MIG/TIG weld, rivet, and screws
- - - - - - - - Needs trimmed to length
- Flats
- - - - - - - - Holes already drilled (most recently front trunion holes not drilled for adjustment)
- - - - - - - - Needs heat treated
- - - - - - - - Needs top rails bent
- - - - - - - - Needs sides bent
- - - - - - - - Needs lower rails attached via (in order of preference) spot weld, MIG/TIG weld, rivet, and screws

And the three methods:

- Rivet
- - - - - - - - Requires modified bolt cutters
- - - - - - - - 12 ton press for barrel removal and installation
- - - - - - - - Go/No Go (and possibly Field) gauges
- Screw
- - - - - - - - Doesn’t require the above tools
- - - - - - - - You will need screws/tap/ and a careful, steady, and straight drilling/tapping hand
- Welding
- - - - - - - - MIG/TIG
- - - - - - - - - - - There seems to be a great divide on this; some say MIG will hold others say no.  I think when the welding fumes clear it is a matter of skill and equipment.  

Kits range from the Romy to the Krink.  Most seem to suggest starting out with the Romy.  

So how correct is what I have so far?  I want to add to it and make it sort of an all exclusive NEWB guide.  If I am on the right track I plan to add links galore.

What is the best way to attach the lower rails?  I have access to a MIG welder via a friend but no experience.  I can buy a spot welder for about $150 that should do the job.  Thanks

edited to add some links and spacing

Well, you basically have it all right however to really do it right (and this is just my opinion, well that and the rifle's creator)

There is no such thing as welding or screw building.  I know lots of people have done it and do it... My first build was a screw build...

However I have since taken that apart and riveted it.

My logic was as follows...

Why do it if I'm not going to do it right.  

That's not to say that you can't screw build, or weld and have a fully functional AK, but it still isn't right...  Not to mention screw building is actually harder than riveting after a little practice.

For what it's worth, that's my view of it.

Reserved for links to receivers

Reserved for links to "How To's"

To be honest I have attached ALL my rails with an arc welder.  I have 10+ builds with arc welded lower rails with thousands of rounds through them with zero problems.  I use the plug weld method where I drill 4 holes through both the receiver and rails then I weld the holes closed, thus joining the rails to the receiver.  I also add a small bead of weld to both the fronts and backs of the rails on the inside of the receiver.  The reason I did it this way at first is because I was told that it couldn't be done, and well, that sounded like a challenge to me!
If we all believed everything we were told about building AKs then a guy called 555th never would have developed the flat bending jig and hcpookie never would have made the first bolt cutter rivet tool.  Innovation is what keeps this hobby of ours interesting.