To get dog hair off your blankets first take the blankets outside and shake them to get as much hair off as possible.
This will remove the loose hair from the blankets and then you can use a vacuum cleaner with a brush attachment to vacuum off as much dog hair as you can.
After vacuuming the dog hair off the blankets take a damp washcloth and wipe it on the blankets which can help remove the dog hair.
You can also buy a pet hair remover for upholstery and blankets which you wipe over the material and it will lift the dog hair off the blanket and upholstery.
You can also go to Amazon.com and purchase a handheld fur removal tool for laundry called the Fur Zapper Pet Hair Remover.
The Fur Zapper Pet hair remover has great reviews and only costs around $15.00 for 2 of them in a pack.