A good place to start is the website for Penn's Office of Student Disabilities Services (SDS).
Information about assistive technology tools is available through the SDS website and Penn Libraries' Accessibility guide. Additionally, the Butler Assistive Technology Room on the ground floor of the Van Pelt Library (G 101.11) houses equipment for use with certain assistive technology applications.
PennAccess provides maps and information about accessible features of Penn-owned or leased buildings as well as its campus grounds. Penn Accessible Transit is a service provided by Penn Transit and arranged through SDS.