How did the crusades change Christian views of Muslims?
Actually, there was no "greater respect" for Islamic culture or people as a result of the Crusades; if anything, the distrust and apprehension which marked each side became more pronounced. So great was the misunderstanding between the two sides that the author of Le Chanson de Roland portrays Saladin and other Islamic figures as pagans who worshipped the ancient Greek deities. On one occasion, which Richard Lionheart had agreed with Saladin for an exchange of prisoners, Richard ordered all Islamic prisoners executed in sight of Saladin's army because Saladin was a half hour late to the meeting.
Any knowledge gained from the Muslims--including knowledge of Aristotle and navigation techniques--was the result of the Christian re-conquest of Toledo in Spain. The typical European attitude that Muslims were infidels was only intrenched by the Crusades, and the misunderstanding between the two groups was exacerbated. It is not coincidental that Osama bin Laden referred to the United States as "Crusader America."
Of course, any answer to such a question must be a generalization because different Christians would have had their views changed in different ways.
One impact on Christian thinking that is often mentioned is that Christians came out of the crusades with greater respect for the Muslims and their culture. The crusaders would have seen how advanced the Muslim culture was and would have come to appreciate some of their ways. People in Europe would have seen the goods that increasingly came into Europe (the crusades helped to stimulate trade to some degree) and would have seen that the Muslims were not barbarians. Scholars would have been exposed to Muslim learning and would have been impressed.
However, some scholars emphasize that all of these reactions could also have come from the contact between Muslims and Christians in Spain rather than from the crusades. We should also note that Europeans did not uniformly come to admire Muslims during this time.