Transport:Aconcagua is situated beside the most used road between Argentina and Chile - on the way from Mendoza to Santiago do Chile. There are many long distance buses, that charge the full price of Mendosa - Santiago. There is only one company in Mendosa, that does local connection to Puente Inca (I´m sorry but I don´t remmember the name). Their first bus leave at dix, second at nine, then in the afternoon. It takes 3 hours to Puente Inca, it´s recommended to buy the ticket day before. Also when you intend to continue from Puente to Chile, buses are usualy full, but may be someone has free. Last bus to Mendosa leaves from Puente Inca at nine in the evening.
Equipment:Except the obvious warm and wind-safe clothes I recommend sombrero, long trousers, face-guard cap and long-sleeve shirt because of strong sun. In time of my visit it was possible to climb without the crampons. It was only more comfortable with crampons (on Calaneta), but not essential. Crampons are more important like the ice-axe, that I didn´t have and didn´t need. Nearly everyone wear haevy plastic boots. I haven´t had them and I didn´t have any trouble. Some people in plastic boots told me, they were pretty cold. It´s difficult decision, mostly when you travel long time in South America and you can´t have too many things. But you should have at least heavy leather boots with membrane (I had Planica Comtec - category "D") and perfect socks. Feather wind jacket and feather trouseres are less important, and necessary when you don´t climb at all hazards of weather. I don´t want to tell, that you don´t need this or that. Most important is to know, that the weather is not stable and can change dramaticly. Everytime you have to adjust the climb to the weather and your equipment. There are many people who freezed there or came back with amputations. There are many people, that don´t have experiences (me to) and want to climb Aconcagua not regarding the risks. Please pay attention and return when you are not profesional climber and the weather becomes bad. I was lucky. The weather in the time of my acsent was perfect, but when I was on the summit, it began to snow  and in three hours there was 30-40 cm in Nido and such a fog that we nearly passed the Nido! We were lucky not to have strong wind or storm. Then it would be bad. You can rent crampons for 30, plastic-boots for 40, feather wind jacket for 30 US$ in Mendosa for 3 weeks (not for shorter period). It´s quite expensive, but the price under the Aconcagua is the same, but don´t rely on it, mostly about plastic boots. You can buy a gas-bottle in Mendosa as well for about 5 US$. The gas-burner (MSR) works in 6,300 m good.  When you don´t have plastic boots, give your boots in the sleeping bag through the night,  don´t rely to warm them up in the morning by walking! 
Water: Water in Confluencia contains too much of minerals and can make some gastro-intestinal troubles, but the water from small streams a bit higher is very good. In Base Camp there is a good water. There is no spring then, but there are many snow fields beside the trail and it makes no problem to melt it down and drink it without purification. Only few people use purification pills and it´s hard to buy them in Mendosa. With 250 ml tin of gas you can melt down snow to 6-7 liters of water in such elevation. Don´t forget to give the water into the sleeping bag through the night.
Food: In Base Camp soup costs 2 US$ and supper 8 US$. When you have money, there is no problem for whatever. You can sleep on bet, eat in eating-room, take warm shower, you can let carry up your luggage (120 US$ from BC to Berlin for one backpack, or the same price from Puente Inca to BC on mulas) . You can buy the basic food in Puente Inca. But don´t try to buy your food in Carefour in Mendosa in hurry, you will eat all the time just tuna can and liver cream and you get mad. It was horrible!
Journey: I lost all my luggage with perfect map on my flight home. There are many pages with basic informationes on the web. Puente Inca is in 2700 m. Confuencia (3300 m) is 15 km uphill (4-5 hours). To BC (4300 m) it takes whole day (25 km - 8-10 hours). It depends on weigh of your backpack (main was 35 kg) and I was pretty tired first two days. You can climb to Canada (5000 m) in 2-3 hours from BC, night there is beautiful. Nido Condores (5500 m) is another 2-3 hours. There are usualy some tents in Cambio Pendiante. Berlin in 5960 m takes about 2 hours. It´s good idea not to sleep there and do the last ascent from Nido. It´s only two and half hours more and you sleep much better both times. But in that case I recommend to run up the section to Berlin day before to get to know the way, because still from BC to summit there are many trails - all without any marks - although all go up. But it´s easy to lose the unknown trail in the dark of the morning. Get start at least at four in the morning. There is no climbing on the way and when you walk slowly it goes well. But the stage after Calaneta, where the trail turns to left - there is no foot-path - only rough slope. Slow down here - it´s very very exhausting. It is betray of NP rangers to keep the trail in such bad condition. Descent is very fast, most of time you can slide-down doing long steps in rocky ground. I did the way from Nido to summit in 9,5 hours. I was quite fast still in Canaleta, but the rocky slope traped me for long time.
Security:There is a doctor in Base Campe and me do compulsary examination. Whan you have low saturation of oxygen in blood, you are not allowed to continue. The enter fee for summit cover helicopter flight to Puente Inca in case of accident or altitude sickness. Then ambulance. In high season they have to take down 7-8 people a day in average! Tents are open and more times I let my things,that I´ve brought up, in rocky nest and I was stolen nothing.