Attendance should be taken every class, every day. It is your role and responsibility as a teacher. Set up procedures and routines for attendance. Seating charts can be a helpful visual aid for the teacher to take attendance and learn names. There seems to be some debate about traditional squad lines for attendance.  It is not an uncommon practice and it does serve a purpose.  Several, actually, including  attendance, learning names, and a personal location for warm up activities.  On the other hand, it may take away from those precious moments of activity and instruction time.  Find a balance between attendance responsibilities and maximizing participation.  Just remember, your students are your responsibility during that time.  Do not underestimate this responsibility.