Metro-North Railroad has created a new brochure to explain their part of the direct service that they are planning to run with New Jersey Transit this fall. It is admittedly a complicated task to convey all of the options and nuances that they are trying to get across, but I think they did an okay job. The brochure is linked from a new web page Metro-North put up for this service. You can also download the PDF directly from this link: http://www.mta.info/mnr/html/SchedPDF_vWEB_Brochure.pdf
Edit: This brochure, in all its glossy printed glory, is available in the information boxes next to each of the upper level tracks at Grand Central Terminal, as of yesterday, August 19, 2009.