Most of the paperwork has to be actually done by the candidate, but the process was pretty straightforward.
I had to pay about $500 for the express/priority/whatever-it's-called version of the Visa, plus insurance coverage, plus the fee for a local third-party I used for the application, for a total of about $1500 (that the company was supposed to reimburse but never did).
Unlike the H1-B, the petition for the J-1 can be done at any time.
The J-1 can be extended twice, and is valid up to 1.5 years. It can be upgraded to a H1-B, although this requires leaving the country for a couple weeks in-between.