All forms of viral hemorrhagic fever begin with fever and muscle aches. Depending on the particular virus, disease can progress until the patient becomes very ill with respiratory problems, severe bleeding, kidney problems, and shock. With Ebola, persons develop fever, chills, headaches, muscle aches, and loss of appetite. As the disease progresses, vomiting, bloody diarrhea, abdominal pain, sore throat, and chest pain can occur. The blood fails to clot and patients bleed from injection sites as well as into the gastrointestinal tract, skin, and internal organs. Basically, you just bleed from every orifice.
Ebola Zaire seems to be fatal in about 90% of the cases. Ebola Sudan is fatal in about 60%. We can't really determine a fatality rate in humans for the recently discovered Ebola Tai strain. There has only been one case, and the Swiss researcher who contracted it from a chimpanzee in the Tai forest was critically ill, but she survived (probably due to the intensive care she received in Switzerland). Ebola Reston is not known to be fatal to humans, but very fatal to monkeys.