Look at the other threads in here and you will find the answers to all the questions you asked.
As for jigs, I like teh DPH jigs and they go not include the "no hammer top rail" but I have used the press bent top rail jig from AK-builder and I was nit impressed. I had better liiking bends using a hammer then I was seing using that jig to do the top rails.
The trick with using a hammer is using a smooth steel buck or a hammer that isn't marked up and slow and even blows with the hammer to work the top ral over. Remember that most of the metal of thse top rails get cut or filed off anyways so even a few little dents and nicks will not matter.
There is a lot of old posts and threads in here and building an AK is a lot of fun.
Here are some of the threads that will help you get started:
http://www.quarterbore.net/forums/showthread.php?t=148
http://www.quarterbore.net/forums/showthread.php?t=544
Flat Bending w/ DPH jig -
http://www.quarterbore.com/images/amdbuild2/
There are many other threads in here as well... if you need specific help let us know.