The Neck
This is my work log of how work with the neck progressed:
When doing this, do not forget to think about the body too. There are many things to keep in mind, one example is how the distance of the neck effects the location of the bridge. I made both the body and the neck at the same time.
Before you commence with this you will need to choose what dimensions you want for your neck, you should also consider if you want to use a truss rod or not. I decided the dimensions during the work, but I do not recommend it.
1st of November:
On this day I made another template of the head for the neck. There are still pictures of the old one if you look under "Preparation of the Wood". Anyway, in the pictures you will be able to see the dimensions of the head.
If you want to get exactly a 10° angle, the easiest way would be to calculate the different distances instead. I only wanted to get around 10° so I skipped that part. (If you are interested, my angle is around 11,5°)
2nd of November:
I have now drilled the holes for the tuning pegs. Sadly, one of the screws have been damaged, so I will have to see if I can find a new somewhere. On top of that I have also sawed out the template, as you can see on the pictures.
When I am making the real head later on I will try to get about the same thickness, perhaps a bit less. The thickness of the template is 1,6 cm, but I will probably go with 1,5cm on the real thing.
4th of November:
Today I have decided the dimensions of the neck, please take a look at the following pictures. I have also added some more of the whole balalajka under "my plan".
The scale length is going to be 18,7", and the actual length of the neck will be 14,45" plus the length of the headstock.
I have some more documents that I made at the same time as this one. Please see the following links.
Values:
Distances
Bridge + more on the scale length
Scale Length:  distance. (18,7")
In centimeters
In inches
Empty table, if you want to fill in your own distances...
Now when I know the values, it will be much easier for me to do the work. Try to decide the dimensions earlier than what I did...
This is perhaps the best place for me to tell you about frets, but this feels a bit unnecessary since Wikipedia gives a very good report on this subject. There are not much to add, if you are interested in this subject there are a lot of good sources.
Main article: Fret (< wikipedia link)

Frets are metal strips (usually nickel alloy or stainless steel) embedded along the fretboard and located at exact points that divide the scale length in accordance with a specific mathematical formula. Pressing a string against a fret determines the strings' vibrating length and therefore its resultant pitch. The pitch of each consecutive fret is defined at a halfstep interval on the chromatic scale. Standard classical guitars have 19 frets and electric guitars between 21 to 24 frets (though Caparison Guitars issue guitars with as many as 27 frets).

Frets are laid out to a mathematical ratio that results in equal tempered division of the octave. The ratio of the spacing of two consecutive frets is the twelfth root of two. The twelfth fret divides the scale length in two exact halves and the 24th fret position divides the scale length in half yet again. Every twelve frets represents one octave. In practice, luthiers determine fret positions using the constant 17.817, which is derived from the twelfth root of two (17.817 = (121/12)−1). The scale length divided by this value yields the distance from the nut to the first fret. That distance is subtracted from the scale length and the result is divided in two sections by the constant to yield the distance from the first fret to the second fret. Positions for the remainder of the frets are calculated in like manner. Actual fret spacing does not use this exact value; the fret spacing on the fretboard was also done by trial and error (testing) method over the ages.
The only things that I feel would be good to add is that you should read about zero frets too and if you do not already know this over time frets are worn out. This will depend on what strings you are using, and of course the quality of the frets themselves. A tip from my side is to try to have the bridge, the tuningpegs and the frets made out of the same material.