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.
After reading the owner’s manual for your digital camera, take some time to learn how the flash works. Your camera’s flash unit can make a huge difference in your photography, so learning its capabilities is important. If you are using a digital SLR with an accessory flash unit, create images bouncing the light into a wall or ceiling to see how that changes the light quality of your strobe. Or, if you don’t have an accessory flash, use the flash’s exposure compensation capability to just fire a tiny bit of light or blast a bunch of light into an already bright scene.