You can log onto the Social Security website and they have most of the information that you are seeking on their website. You will just need access to a printer. If you brother does choose to file for disability, he will either need to go to a Social Security office in person; file online; or find someone to file for him -- many attorneys offer this service to their clients. Some attorneys only get involved in a Social Security Disability claim once the SSA has issued a denial.
If it was me, I'd get an attorney to handle the application considering your brother's demeanor. Many Social Security attorney specialists will take initial applications on a contingent fee basis. Attorney assisted applications usually have a much better chance of being approved without the delay and headache of multiple appeals. Additionally, since Social Security rules are voluminous and confusing, an attorney will have a much better idea if your brother should apply or not.