This link describes a program offering laptops for those in school and with a low income.
This may be a good resource if you are looking for a refurbished laptop and haven't been able to save up enough for a cheap, new laptop.
For desktop computers, we have noted that the $60 option at this link is a fairly out of date computer, so you will be better served if you ask for at least a "Dual-Core Processor", even if it is more expensive.
If you would rather not pay shipping or drive to one of the locations, you can also buy a computer at Computer Recyling, a project of The Working Centre. Computer Recycling also provides some computer support to computers purchased here, and is not limited to low-income or in-school eligibility criteria.