Finishing A Stock For An AK-47

There's a LOT of info around on this on many of the forums.
I'll address getting the "Russian Red" color first.
Virtually all the finished stocks you see are WAY too red, even when you take into account that the camera makes them look redder then they are.
"Russian Red" isn't really red.

Here's a site with good pictures of REAL Russian wood. Note that the colors range from light orange, to a red-orange, to a dark red-brown:

http://tantal.kalashnikov.guns.ru/bstakwood.html

There are myriad ways of getting the color.
I personally didn't like the RIT dye both for the way it worked and the large amount of salt that's in the dye.
I finished my AK-74 with Tandy water-based leather dye.
I mixed red, yellow, and cordovan, which is a red-brown. Depending on the wood and what you want, you may be able to use just the cordovan.
Other methods use ready made stains. A popular one is Minwax "Sedona Red". Others have used Minwax Red Oak stain.

Another way of getting the right color and finish is the method used by the Russians.
They used Amber Shellac mixed with a red stain.
You can get the same look by mixing 8 parts of Amber Shellac with 4 parts iodine. You simply apply thin coats until the color is what you want.
You can do much the same thing using Minwax water-based acrylic wood finish and iodine.

For sanding, buy a good grade of medium sand paper and use a sanding block. Sand with the grain, which on AK wood is length-wise.
Since the AK was a military rifle, you don't want a real smooth, glassy surface. This saves a lot of sanding.
In addition, you have to be careful because many stocks won't allow much sanding or you'll under-size the wood, especially around the butt plate.
It's better to stop than continue trying for a super smooth surface.
This is a judgment call, but most AK wood comes already pretty close to smooth enough.

Sand only the exposed areas, not the parts that fit into the receiver. Stay away from the edges of the hand guards where they meet.
AK wood also doesn't fit like commercial wood does. There will be gaps and mis-matches.
Most people make the mistake of trying to make the wood look like a commercial rifle stock and sand too much, causing undersized wood.

If you're going to stain, stain the wood and let it dry thoroughly. Check color outside in the shade to see the true color.
After staining and drying, apply whatever finish you want. Again, there are MANY finishes from oils to shellac to polyurethane.
Also again, the AK finish is not real smooth. It usually has brush marks in it.

Here's how I did mine:

Sand only to remove major rough spots or irregularities left during manufacture. I used a good grade of medium sand paper from Lowe's and a sanding block. I did very little sanding.

Apply stain using water-based leather dyes. Let dry, then check outside to determine the color.

Apply a well-thinned coat of satin finish polyurethane Minwax finish.
Sand very lightly between coats with a green synthetic polishing pad. Most hardware stores sell these, or you can buy them in most grocery stores as pot scrubbers.
These are about the right "grit".

Apply 2 or 3 more coats, thinning the coats with about 3% or so of thinner for good brushing.
Don't sand the final finish. Let the finish cure for 4 to 7 days to reach full hardness.

I'm not trying to tell you how to do the finish sanding, or between coats, but instead of the "pot scrubbers" mentioned, try some 000 and 0000 steel wool. Using the 000 first, after applying the finishes, then the 0000 wool during the final, final stages of smoothing the finish out. I just finished an old Rem. model #33 .22 rifle this way, wood is so smoooooth. YMMV

"...haven't added tung oil yet..." Hi. Get the colour the way you want it before putting any tung oil on it. Tung oil will keep everything out. Gives a hard, waterproof, finish that will also bring out the wood grain, but the staining must be finished first. A bit of mahogany stain might give you more red, if that's what you want. The Soviets didn't spend a lot of time/money of stock finishes though.
You may want to do a bit more stripping on the grip.