Using the microscope.  There is a diagram of a compound microscope in the appendix of the lab manual, and there is also one available on a rolled-up poster that can be taped to the wall.  In addition, there is a link to 'microscope hints' in the Lab Policies section.  For practice, it is good to have the students try to focus on Spirilli bacteria.  They can see the pink smear on the 4X, then slowly progress thru the lenses until the spirilli are visible at 100X.  The slides of the other two bacterial types aren't very good.  Demonstrating this on the overhead scope is a good idea.
Kim wipes are available for cleaning slides off after oil immersion.  The TA might want to purchase more oil from the biology stores.  It is important to stress how to clean lenses--both the objective and the optical--with LENS paper only.  I tend to have students work two at a scope, and each one has to clean the lenses...hopefully, this leaves the lenses clean for the next class.
The microscopes being used cost well over $2000 apiece. Please treat them with care; a damaged lens might be difficult or impossible to replace.  Students should use only lens paper and clean them as demonstrated by the TA.  For an EXTREMELY dirty 100X oil immersion lens (and occassionally for a 40X lens that was used with oil) the lens can be unscrewed and cleaned while off the microscope.  This is not recommended otherwise because the lenses can be dropped and are the most expensive part of the scope.
All scopes missing any parts (blue filter, diaphragm/condenser, burnedout bulb, etc) should be reported to the TA.  Replacement parts may be obtained from the repair shop across from the biology stock room or the stock room itself.