I want to tell you about one of my favourite webs around: The Cursed Monkeys
They are a group of spanish painters and sculptors that really enjoy this hobby, and they make amazing painting jobs. They are a real inspiration for me. The web is both in Spanish and English, so anybody can follow them ;-)
If their web you can find links to the blogs of the members of the group (in case you want to order a commission), it also has a gallery with their minis, and they also post regularly about their collaborations together. As I mentioned, some of them are painters, and some are sculptors. Sometimes they create the minis from scratch, and then, they do an amazing painting job.
They have some really good step by step tutorials ( I already mentioned this one about painting Ultramarines with an airbrush), and lately, they have even started to make video tutorials!
This web is a must if you are looking for inspiration or some guides to improve your painting. They definitely helped with mine.