I, have 4 years experience in C# ans MS SQL, i have similar app. this manage 3 type of users, admin, teacher and student, the admin create the users (teacher and students), the teacher create the practice and enable / disabled the students for this, him can upload file(s) and images. The student can use the practice and this have access to the files that teacher upload. this system has develop in PHP and MySQL but i can traslate to VB and MS SQL.