There are way more tutorials available on the internet than those listed here.
I believe that the best way to learn how to make miniatures is... by doing it! :) In countries with tradition on dollhouse miniatures it is possible to take classes in workshops at shows, organization events, and at the very renowned IGMA Guild School. Local clubs also get together regularly and often share a common project, where each member will work on their own personal version of a shared idea. There, the more experienced members will gladly help and guide the novices.
Well known magazines also offer tutorials on regular basis. It is really worth subscribing to at least one of them, even if you choose the online version, to save shipping costs. Check the options at Read Minis.
Some professional miniature artisans in Brazil do teach classes too. Like Angelo Pinheiro, Betinha Murta, Ivani Grande, Regina Nachtigal and Regina Passy-Yip send me an email if you need their contact info.
Another way to learn, and it is a free one, it through the available online tutorials you can find all over the internet. From the menu on the left you can navigate through the pages that contain tables with links to various tuts, all organized alphabetically and by topic. You can visit the tutorials available in Portuguese, in several other languages, and some on how to assemble kits DHB has developed to help the Brazilian newbie. Choose your tutorial, gather the material required and... have fun!!! :)
Courtesy About.com Miniatures, a website with loads of tutorials!