World War Z is important to read in this case. Remember, they are decomposing. Rifles are a poor tool to work with. You need a halberd type weapon, like a really strongly made (read, not home depot) hoe, or shovel. Remember to take the high-ground. And move to northern climes...regardless of a zombies resiliency, they will still freeze (organic material) If you do move north, remember to go to high altitude unpopulated areas, both for resource conservation and so that you can take high positions over the hordes.
Burn zombies immediately in summer months to stave off diseases.