Contact Western Oregon University if you want to learn sign language for vocational purposes. The university offers a bachelor's degree in American Sign Language Studies, as well as in American Sign Language/English Interrupting. The courses offered are open to all students of the university. Therefore, if you are a student interested in learning, but not as a major or minor, you can still enroll in the classes.
To learn sign language to communicate with your child, contact one of a number of baby sign language classes.The Portland Early Learning Project offers groups for children to learn sign as either a first or second language. The groups are divided into various age groups beginning at 5 to 24 months and continue until preschool with the 3- to 5-year-old group. Prices are normally charged per family, rather than per child, and they do offer classes outside of Portland. There is, however, extra cost for those classes.
See the Portland Community College for courses on sign language interpretation or sign language studies. They offer courses not only on the language of American Sign Language, but also on deaf culture and history.
Oregon's Deaf and Hard Of Hearing Services offer a number of resources for those who are hard of hearing or who wish to learn more about sign language and culture. Their reference section covers not just courses and references in Oregon, but the entire United States.
Try a private teacher. Online forms like Teach Street or WyzAnt feature people who are willing to offer private lessons in a given field, including sign language. Private teachers can give lessons around your schedule rather than you having to fit them in.