Nomad Travel were excellent - they provided much better medical advice than my own GP and helped us put together a personal travel pack and at very reasonable cost.
Invest in a good down sleeping bag, you won't regret it, and we used the lightweight blow up mats from Therma Rest, these were very comfortable and warm.
Take plenty of one dollar notes - we did not and it felt awkward when we could not tip as we only had large currency, once in Tanzania it is hard to get any further dollars and tipping is widespread and all done in american dollars.
Do not buy a hat that is not adjustable and can be loosened off. Everyone in our group had to cut their hats as we got higher as they really started to dig in and this does not help with any headaches. This is the same for sunglasses, they need to be fairly loose.
Aspirin seemed to be the leaders drug of choice for headaches rather than Paracetomol or Ibuprofen
The leaders did not encourage the use of Diamox unless you showed symptoms of AMS and they would then recommed when to take it. In fact they did not want you to take any medication without telling them first, including headache tablets. This way they could moniter you much better for AMS than if you were trying to treat yourself. We purchased Diamox to take with us so if we did have to use it we could at least take our own medication but luckily neither of us had to use it. Others in our group did take it in the final 2/3 days but it is difficult to know if it really helped as it certainly did not cure their symptoms, although the AMS may of got worse without it.
Keep drinking - those in our group that drank anything less than 3 litres whilst walking certainly seemed to develop symptoms of AMS much quicker. Those that used water bottles seemed less inclined to keep reaching round to grab a drink than those that had a bladder and drinking tube close to your mouth. I veiwed my water as my medicine to prevent AMS and kept sipping every few minutes. This certainly worked for me and I had no AMS symptoms at all over the whole trip. By day 5 I had up'd my water intake whilst walking to 4 litres and grabbed any oppotunity to have drinks with our meals as additional fluid.
Keep eating - even when you really don't feel like food you must eat! Take plenty of nice snacks with you and boiled sweets. I found Power Bars good and they are light to carry and certainly give you a long lasting boost.
Take at least a 35 litre ruc sac - you don't have to fill it but it makes it easier to pull clothes out quickly if you haven't had to squash them in. On summit night you will take and use all your clothes as by 3am its very cold and you are not generating any heat as the walking pace is very slow. This is when the larger sac really helps.
Train before you go - best form of training and the only training we did was walking and lots of it, especially using the walking boots you'll be taking with you. We trained with heavy ruc sacs and this really helped us on Kili, not that you carry a really heavy pack it just meant we were used to it.
Washing - you are provided with a bowl of hot water at breakfast and before dinner. Take a light flannel and we used baby wipes as a top up. Take 2 hand gels, we kept one in our day pack and one in your wash kit.