Actually, it's possible that the bar association will have some free advice referral service, but nowadays, pro bono referrals are most often handled through legal aid and legal services offices, even if in cooperation with the bars. If you can afford SOMETHING, however, some bars have a low-cost panel of attorney who will take a case at a flat fee or a reduced hourly rate depending on the type of case.
But whether you go through Legal Aid or the bar, I will tell you up front that relative to the need, the "pro bono attorney" is largely a theoretical construct. It is extremely difficult to find an attorney to take a case for nothing. Would you work for nothing? It's an aspirational thing, where lawyers, as privileged members of society are understood to have some obligation to lend service to the poor in the interests of equal access to justice. Some places make lawyers REPORT whether or not they do any pro bono, but there is nowhere that is is mandatory that they actually perform such services. So if you find one who seems even remotely willing, remember that you are asking for a huge favor, and they don't have to help you if they don't want to.
A little ass-kissing wouldn't be out of line.