Depending on his situation, and on how bad things really are, he may have several options.  First, before he can file bankruptcy, the law requires that he attend credit counseling.  Follow this link to a post about credit counselors.  The fees range from $75 to $125.  Some counseling services offer fee waivers or reductions for those who are truly broke.  The counselor may be able to help your brother avoid bankruptcy or give him some tips about saving the money required to file. 
 
Many Massachusetts bankruptcy attorneys offer a free initial consultation.  Your brother can take advantage of the consultation to find out how much money he will need (up front) if he wants to hire an attorney to help. Frequently, once the attorney starts the bankruptcy proceedings and ends collection efforts by creditors, the debtor may be able to free up money that can be used to pay legal fees.  For example, in some cases, a debtor may stop making credit card payments for a month or two before filing and use the money to file bankruptcy.
 
He can also apply for a fee waiver and then attempt to file his voluntary petition on his own.  Bankruptcy can be tricky, so this is not the best option.  Before filing, he should get a book from the library and study up on the type of bankruptcy he intends to file (Chapter 7 or Chapter 13).  Also, the United States Bankruptcy Court  for the District of Massachusetts has some helpful information on its website, including videos and FAQ's about bankruptcy basics.
 
Finally, if your bother is truly flat broke, he can try to find an attorney who will work at a reduced rate or pro bono.  For that information, he can check out the MA Bar Association or the Legal Advocacy and Resource Center.
 
Hope that helps.  For general information, tell your brother about our Massachusetts Bankruptcy Discussion Forum.