Water Pump/Thermostat

My MR2 has been having alot of troubles recently (very sadly) and the most recent one seems to be coming from the water pump. I have a large coolant leak somewhere in there, it feels like a broken hose underneath the pump, and am going to replace it now. I was curious how other people have found the easiest way to access the water pump and take it out. I am also going to replace my thermostat while I have it out. I thought going in from the top, since I can see it, but there are a number of other hoses, wires, and the cross bars in my way. Would I be better off going to it from underneath, I can lift it up and work on it if need be. Also, I can feel a large gash in a hose which is damp, although I'm not sure if it is a coolant hose or an electrical line of some sort. If someone has a link to a diagram of the water-pump and coolant system labeling the hoses and parts and their jobs which they could link to me, that would be awesome. The hose is a short rubber one connected to the bottom of the water pump running in an L-shape in to what seems the bottom of the block (although, I can barely see it, and am just going by what I can feel sticking my hand deep down into my engine). Any infortmation on this at all would be greatly greatly appreciated.
Many thanks,
Matt