After a request is sent, the expert is notified and has 7 days to respond. They may also request for more information in the private messaging area. You will be notified about this. Once the expert accepts your request, the contact information is shared and you are free to contact the expert and setup a time to connect. This can be done via phone, email, skype, in-person, etc. You can specify various methods within the profile which is shared only if the expert accepts the request.
You can see the status of each request in your "Requests" section.