Accessible Faith: A Technical Guide in Houses of Worship (PDF, 54 pages: see pages 22-24) has specific information about worship space, with ADA wheelchair seating requirements clearly explained. The booklet describes ways to shorten pews and create accessible seating areas.
Accessible seating means seating not only for people using wheelchairs or scooters, but also for people who are large; people with hearing or vision limitations; people with chemical sensitivities.
It is not okay to force people who use wheelchairs to sit in front of all the pews or behind all the pews because there is no other seating option. Segregated seating is not an acceptable seating arrangement.
Some sanctuaries have movable, or interlocking, or folding chairs. Sometimes these chairs are too narrow to be comfortable for people who are very large. It is welcoming to offer some chairs that are wider and/or more substantial for people who need them.
Some people have difficulty getting up from a chair that doesn't have arms. It is welcoming to offer some chairs with arms for people who have knee, hip, or leg problems. It can be pointed out during announcements that it would be welcoming for people to save these chairs for those who need them.
Have seating spaced so there is extra legroom for people using crutches, braces, walkers, or who are wearing casts.
Fragrance-free seating areas are becoming more common, and can be a blessing for people with sensitivity to scents. When planning a fragrance-free area, keep in mind the path people will have to take to get to there, making sure they will not have to pass through a high-fragrance area.
Fragrance-free seating areas are only one part of a multiple-chemical sensitivity policy.
Providing adequate lighting in your sanctuary can be difficult if it is an older building. Printed materials in larger fonts help compensate.
When your church offers large print orders of service, or has an assistive listening system, or has Braille and/or large-print hymnals, offer these resources in a way that helps people accept and use them. Some people feel stigmatized by their need of large print or amplification; find the outspoken lay leaders to "talk these things up"—to use the offered orders of service, etc. Make it a positive thing to do.
Do what you can in your church to make your chancel accessible so that people with disabilities can lead services. Install a wheelchair lift; mark the edges of steps with light-color strip (for people with limited vision); have handrails on both sides of the steps; build a permanent ramp (or have a movable ramp). While not ideal, a music stand can be used as a substitute pulpit to hold pages for a speaker who is seated.