Hi Amin,
I can tell you how I started the process but again I should tell you mine was based on No objection from my home country and my reason was because I want to join my partner who lives in US. I don't know if you have a sponser for job (getting H1, working visa) or something else and honestly I don't know so much about those cases. Here is what I started:
Go to the State Department's website:
https://j1visawaiverrecommendation.state.gov/accessController.asp?page=7
and fill out the application online
At the end bunch of filled out forms will be created in pdf format
Make sure to save it somewhere in your computer
print all the forms
One of them needs to be send to your home country embassy (that was my case, don't know about your!)
Mail rest of the forms to US State Department, there is a instruction on the website and also on first page of created pdf forms.
When you fill out the form online at the end you will also get a case number and with that you can follow your case on DOS's website.
That's about all you can do rest of it is out of your hand.
Hope that helps. Good luck