1. Sign up/Register:
https://gotranscript.com/register (you might be taken to the order form after this step, ignore that and follow the steps described here).
2. Study the guidelines:
https://gotranscript.com/transcription-guidelines.
3. Study the samples that are in the guidelines.
4. Take the test:
https://gotranscript.com/transcription-jobs. Click on APPLY NOW and select your language.