You can save the values to object of an class and then the object to the session. Then later you can retrieve the object from session.
Example:
Student objStudent=new Student();
objStudent.Name=txtbox1.Text;
objStudent.RollNumber=txtbox2.Text;
Session["student"] = objStudent;
You retrieve data back from session like-
Student objNewStudent=(Student) Session["student"];
Now you can use the properties as required.
Hope, it helps :)