@CardoMondo
All you need to know is included in the links at the beginning of the thread. Crisp Thinking is 'Potato'. Most of the jobs require a degree of concentration as they are quite boring, so you will need to consider if this is the right fit for you.
For Appen you need to go to the Appen Connect website and register and upload a cv. Once registered you can apply for a variety of 'jobs' - descriptions are provided.
Clickworker tends to pay a month or so after you have done the work for the eye tracking one. You can see the payment dates of you look at your work history.
Some people discuss matters that are to do with the jobs they are on, it's not meant to be obscure, but there are obviously things that are meaningless to anyone not doing them.