Bart, once you have played on one of the Blocktopia servers for at least a month, you can apply for Trusted on that server. This is to ensure that you are solid with the rules of the server and know how it runs. To make your application, you will need at least to Operator+ references in which they
directly tell you they will either be your reference, or that you should apply. But a Trusted also has to be dedicated, responsible, trustworthy, and mature. To make your application you post a new thread in the Applications forum for the server you are applying for. You also have to follow this template ->
http://blocktopia.net/forum/threads/trusted-application-format.143/ This thread also informs you of the process of applying for Trusted and how the voting is done.
Hope this helps! Feel free to ask any more questions if you are still unsure of something! :)