I'd recommend this article, even if it was written as a warning about Americans building their own AK's. There's a little decent information in it, and of course there's the usual misinformation. Still... knowledge is never wasted.
I feel the need to point out one important point. The author never wrote about heat treating the receiver for his AK. I know very little about building guns, but I do know that the firearm isn't going to last long if that step is skipped.
I Built This AK-47
So was the AK build legal? It must be since some guy on a blog and a Lefty website said it was.
Give the post below a look, and consider whether or not you want to take some amateur's (especially when it's a "Journalist") word on the legality of building rifles in your state.
Committing Multiple Felonies In CA When Building An AK