Karel, I am just painting my first 1/35 figure for years with the help of a fantastic Osprey book called "Modelling Panzer Crewmen of the Heer" by Mark Bannerman. I recommend it no matter what type of figure you want to build, not just if you're doing PAnzer crew. In this book they do talk about using acrylics, but mainly enamels and oils. Personally I find acrylics virtually impossible to use with a brush...
A few tips from there - number one, use a light coloured undercoat or primer.
Keep the paint thin, as Anthony said. Detail is often very "weak" on figures and thick paint covers it up easily. With enamel or oil it is possible to spread very thinly, and two thin coats are better than one.
Put it under a drinking glass when drying to prevent dust falling on it.
When shading or highlighting, don't just do one shade lighter or darker than your base colour - do another in between. If using enamel, you may have to shade or highlight when the previous coat is dry, but with oil you can do it when the coat is half dry, which makes blending the shades much easier.
Although it seems the wrong way round, I think it is better to paint the belt and boots first, then the clothes. It is easier to get the right join.
Don't use stright black for anything, always lighten it a bit - in this book they use flesh colour to lighten it, which stops it from just turning grey which is what you get if you add white.
The belt and boots look a bit too flat black - leather fades a lot when worn. Try some subtle drybrushing on the edges of the belt (another good reason for doing it first...)
Stick it on a temporary stand so you can handle it without touching it.
The shading does show in your photos, try to keep it closer to the original colour, your jacket shading looks a bit grey.
Take great care where the colours join - belt to jacket, cuffs to hands, boots to trousers - getting this wrong and overlapping the paint can spoil the whole thing.
Be patient and let stuff dry before doing more - sometimes this means a few minutes a day on that figure only, and then go and do another kit.
Anyway - good luck with the head ! ! That's the hard part!