After mounting the miniatures I used a black primer to prepare the models for the paint. Afterwards I looked up some pretty pictures of already painted models and decided which colors I want to use. Then I started with painting the bigger areas, until after some drying phases I finished the models with small stuff like painting eyes or armor (special metal colour available for that purpose). I definitely can recommend Valllejo colors, as they are of great quality and stick very well to the miniature. For beginners I think it's a good idea to start with some set of colors (16 different colors are in there), for me it was definitely enough.
There are a lot of online tutorials available for improving your paining skills (a google search should proof this), e.g. how to paint shades. To be honest, for the beginning I just wanted to have some simple painted models - without spending huge amounts of time and effort on this subject. So I just focused on some quick and straight-forward painting, which I not only enjoyed doing but which fully served my purpose. So, just give it a try - you will see it's fun!
You can buy these fine stuff @ fantasy-in.de
Vallejo Game Color: Intro Set
Hobby Brush - Starter Set
Other articles about Hordes:
Hordes: General Introduction
Hordes: Trollblood Army