Don't be bashful! If you want comments, give comments. You don't need to be an expert photographer to express your opinion about the work of others. You don't need to go into great depth. A simple remark about cropping, composition, color, subject matter, etc. can be of just as much help to a budding photographer as an in-depth critique.
For this assignment, seek out a scene that is very rich in texture. The lighting will probably be raking across the subjects to create this texture. Create a dynamic composition that looks good in black and white. Early morning or late afternoon light usually provides this cross-lighting effect when outdoors. You can use midday lighting as a source to create texture, but your subject needs to be top lit for the high sun to act as a cross-light. Old buildings with peeling paint and weathered wood work well. Take you best shot and post it on the Web site.