1) Perhaps a rather obvious comment is, 'don't run out of drinking water'. We easily got through two litres of water a day each, and had an extra 1 litre bidon that was also usually finished. We now take an extra 2.4 litre Platypus bag in a pannier for really hot days and have 2 litres of water on each bike.
2) We found our total fluid intake was probably around 4 litres a day. In the evenings we also drank lots of tea, both during and after dinner. We took enough (Coop 99) teabags to see us though the first half of the trip and discovered 'good' teabags in supermarkets (Twinings?). In mornings we kick-started our days with strong coffee. Norwegian filter coffee is generally very good indeed.
3) Keep high energy food and emergency meals close to hand. We took a mix of high energy foods, dried fruit, chocolate, and nuts for variety. We also packed some dried meals just in case we needed warm food in a hurry. You can get complete meals from outdoor shops, they don't weigh much, are ready in a few minutes, and are full of calories (and the ones we have tried are very tasty too!).
4) It appears you cannot buy methanol for Trangia stoves in Norway. The best available product is 'Fin Fyr', otherwise use 'Rød sprit' (ethanol) and add a bit of water. 'Rød sprit' seems to be sold in most petrol stations, sometimes you can find 'Fin Fyr' as well. Otherwise a fishing tackle shop or shops like Perry Sport sell 'Fin Fyr'. Gas canisters are more widely available than ethanol.
5) We used about a litre of fuel alcohol a week which we thought was OK. Our pattern included stopping at least once a day to brew up some tea, in addition to a cooked dinner in the evening, and boiling water for coffee at breakfast. We were happy with the silent operation of the Trangia, but may buy a gas or petrol burner adaptor for the cooker in the future to give us more flexibility.
6) Brown cheese is heavenly. Go for the pre-sliced varieties as it makes sandwich making easier.
7) Supermarkets open quite late and seem to be dotted a convenient points on the route. If you get really stuck then many petrol stations have a reasonable range of food and other products.
8) We found dried soups were a good way to re-hydrate at the end of the day. They also don't weigh much and can be combined with pasta to make a quick high carbohydrate evening meal.
9) Buy heavy items like fruit or fresh veggies at the end of the day close to your campsite.
10) We found we had no problems with food as vegetarians. Every now and again we found a health food shop which gave us a bit of variety in our diet. Sometimes supermarkets had products such as tofu or soya milk products or meat substitutes. We discovered we had to read soup packets to be sure that they did not contain meat but otherwise we had few problems.
11) Face cleaning tissues make excellent hand wipes. They are by far and a way the best way of getting oily hands clean (after you have put your chain back on for example) without a supply of water. One is enough to clean up a pair of very oily hands.
12) Milk turned out to be problematical. Most of the time we could only get 1 litre packs. This meant usually carrying an opened pack round for a day or so, which sometimes leaked, and was another half kilo to cart around. We now take packs of dried skimmed milk power with us, and only occasionally buy (liquid) milk when we know we can finish it quickly.