Drive the route and get to know it but to be honest it didn't help as much as knowing where to park and deliver. Learning the streets will come easily. Some things I recommend are...
Come in early every day. I mean at least a hour early. Get organized and go through your truck every morning. Familiarize yourself with where your stops are in the truck. Some may disagree with this because you are working off the clock. They are right but during the first 30 days do everything you can to give yourself a advantage.
Pay attention to delivery locations in the businesses. Don't be afraid to ask where they want it the first couple times. After that take it right there every time without asking. The biggest time saver I've always found is knowing exactly who will sign and getting his/her attention as I drop the packages.
Find out who usually does the route. Be polite and pick his/her brain. Then find the person that covers the route the most and do the same thing.
Pack your lunch all 30 days and eat while sorting your truck. (Stop this immediately once you qualify) the numbers are not on your side so this will help even the odds.
One last thing that I tell new guys to do. Every week ask the OR how you're doing. If they are anything like here they won't tell you anything until they are disqualifying you unless you ask. Keep your shop steward inform of what they say and your progress. Just in case they try and DQ you for no real reason.
Good luck.