Any tips for growing hair for dreads?

I am Caucasian with thick brown straight hair. It is not curly or wavy but starts to curl at the tips once its 3in or longer. Im trying to grow my hair out for dreads and I wanted to know if there is any tips as far as what not to cut, what to do with side burns during the growing process, is there any type of shampoo I should be using during this period, Any tips appreciated.