Jerry Hartley put together a website which has a great caresheet for rosys:
http://www.localityrosys.com/husbandry_propogation.php . With a few minor deviations, I've had good results following his guidelines with my rosys. I've heard some anectdotal reports of increased risk of respiratory problems with pine shavings so I prefer to play it safe and use aspen. I also tend to feed a bit lighter, giving my snakes 1 appropriately sized rodent every 7 days unless they're a female I'm prepping for breeding. My guys are coastals, however, which are reputed to be less prone to regurgitation problems when fed large meals so those feeding frequencies / numbers may be different because smaller more frequent meals are better for the desert localities.
-Alice