Mounting a scope on an AK can be easy or difficult, but it can be done. There are several ways:
1. Use a long eye-relief, low power scope. The mount for the scope an rings can replace the rear iron sights or attach to a set of upper and lower handguards with Mil-Std-1913 "Picatinny" rails attached to them. This works, but it looks kind of funky and you have to get used to working with a long eye-relief scope. (The long eye-relief scope on a rifle is similar to that installed on a pistol. In the case of the pistol the scope requires exteneded arms to use it. For a rifle, the low power scope is mounted forward on the rifle about 8 to 12 inches from the shooting eye.)
2. Use a modified receiver dust cover with scope rings attached to it. This is absolutely the WORST way to attach a scope to the AK because the dust cover fit is sloppy and the cover itself flexes like crazy as the gun operates. A scope requires a solid mounting surface to work and the dust cover provides none of it.
3. Use a Russian-designed "universal" mounting rail that attaches directly above the trigger guard on the left side of the receiver. I prefer this method. Many factory-built AKs have this rail already riveted to the receiver. There is at least one or more outfits that offer aftermarket installation kits with all the necessities for installing the rail. Some require riveting and others use screws, but all work. You will need to use a Russian-type throw-lever mount for this kind of scope setup. K-Var in Las Vegas makes the best and they have different variations that will allow just about any kind of optic to be mounted on your rifle.
I've got three Romanian AKs. A SAR-1 in 7.62x39, a SAR-2 in 5.45x39, and a SAR-3 in 5.56x45 NATO. All have stamped steel receivers (like the Russian AKM), all have U.S. plastic furniture (the new butt stock adds needed length of pull) that's tougher and better than the wood, and all have the Russian-designed universal mounting rail that is attached on the left side above the trigger guard (factory install). Thie rail is simple and provides positive lock-up for the actual mount and rings.
OK, how well does it work? I put a K-Var mount on my SAR-2 (5.45x39 caliber) and topped it with an ATN "UltraSight" (a halographic quick-reaction sight). The sight LED projects one of four reticles -- dot, dot in a circle, dot in a circle with crosshairs, or crosshairs -- onto a piece of optical glass. This is much like a fighter plane's gun sight. You look through the non-magnifying glass and the reticle seems to float on air over the target. The brightness of the reticle is adjustable for bright sunlight to darkness. Once zeroed, the sight is NOT affected by misalignment of the head behind the sight -- the main problem with conventional telescopic sights. With this rifle and this sight arrangements, I was able to put two round double taps on a steel silhouette target's head at 75 to 100 yards. Consitent body hits were attained at 200 yards. This is a very good rig.
My SAR-3 (5.56x45 NATO caliber) has a Russian PSO-8x42 scope. This Russian design comes with an integral mount. The scope has an illuminated reticle. This is a very good scope -- it also looks VERY Russian, that's to say clunky -- and it works very well. The reticle is a ranging type reticle similar to that of the Russian SVD sniper's rifle in 7.62x54R. This reticle is calibrated to 7.62x39, 5.45x39, or 5.56x45 NATO. Another bonus is a sliding sunshade to prevent glint from sun off the objective lens and the Russians provide a permanently attached rubber cover to protect the front lens glass. The occular end of the scope (closest to the eye) has a very soft rubber bellows to help focus, keep bright light from disturbing one's aim, and protect the glass on that end of the scope.
At his time, I haven't decided on the optics for the SAR-1 in 7.62x39.