Almost every class at Lehigh handles homework in a different way. Some classes have homework due on every lecture day. These are usually shorter assignments that will take 20 minutes to an hour and a half each. These may be written assignments or online submissions. Other classes have homework due once a week. They give you problems at the beginning of each week, which need to be turned in at the beginning of the following week. These assignments typically take 2-4 hours each. Homework in either of these kinds of classes will probably count 10-20% of your grade. Other classes, in particular computer science classes, will have 6-8 homework assignments throughout the semester. In the case of computer science classes, these assignments will take you 3-8 hours depending on how well you know the material and how big of an assignment it is. In these kinds of programming classes, these assignments may count as 5% of your final grade each.
There are also many classes who do not count homework as part of your grade. Sometimes there will be weekly readings that are expected and there may be pop quizzes in lectures. Some professors like to assign problems but not ever collect them for a grade. In this case, the problems are assigned just as a self-check to see if you know the material. Although it is rare, there are also classes that do not give homework at all. Your grade may be determined solely from exam grades. Some people prefer these kinds of classes and others do not. No matter what kind of homework assignments you are given it is always good to know people that you can check homework with or ask questions to if needed.