I'm preparing for a multi-day backpacking trip. What are the key recommendations from American Hiking Society for waterproofing my pack and distributing weight for optimal comfort, especially concerning my sleeping bag and heavy items?
Navigate to 'americanhiking.org' Go to the 'Hiking 101' section. Click on 'How to Pack a Backpack'. Identify and extract the recommendations for waterproofing a backpack. Identify and extract the recommendations for distributing weight, specifically regarding sleeping bags and heavy items. Synthesize these recommendations into a concise answer.
State that a good pack cover keeps both the pack and its contents dry, and recommend putting clothing and electronics in resealable plastic bags or lining the pack with a trash bag. Mention that stuff sacks with down sleeping bags should be lined with a plastic bag, especially if on the outside, because down sleeping bags must be completely dry to be effective. State that heavier items should be kept close to the back and higher up in the pack to maintain a center of gravity and prevent back strain. Confirm that the sleeping bag belongs at the bottom of the pack, or lashed to the frame below the pack itself for external frame packs.