Learning the Trade
I'm sorry, but we do not maintain a list farmers or ranchers looking for free help. It might be helpful if this friend had some idea what part of the state would be preferred, and then perhaps contact the local County Extension Agents in the relevant counties. These agents maintain close ties to the farmers and ranchers in their respective counties, and could possibly direct you.
Links to the county web pages for all counties in Texas is available at http://counties.agrilife.org/. The website for each county includes contact information for the agents.