It looks like the governments around the Salem-Keizer area make it a little tough to access affordable housing services. Although, the area is not that geographically large, it has at least three different government agencies providing low-income housing services. To make it tougher still, each agency appears to have its own little niche geography that it covers. The most populous area is covered by the Salem Housing Authority, so I would start there first.
The Salem Housing Authority covers the City of Salem in Marion County, plus the City of Keizer (phone: 503-763-3102; web: http://www.cityofsalem.net/sha/
The Marion County Housing Authority has its office in Salem, but the area it serves is those unincorporated parts of the county that are outside the Salem-Keizer urban growth boundary (phone: 503-798-4170; web: http://www.mchaor.us
The West Valley Housing Authority covers West Salem but, because West Salem is in Polk County, the WVHA has its office in Dallas (phone: 503-623-8387; web: http://www.wvpha.org
If these agencies can't help, they ought to be able to at least direct you to resources that are helpful.