Most adherent cells should grow on glass just fine with no poly L lysine treatment. Some tricky cells (e.g. 293) might require poly L lysine so that they don't spontaneously detach. Chamber slides are nice, since they will allow you to use less reagents for later processing steps. In the old days, we used to just drop sterile cover slips into 6-well plates, and cells would attach just fine to the cover slips. If doing confocal microscopy, the thickness of the coverslips may be crucial, so check with your local confocal expert prior to choosing cover slips. If you are trying to visualize a fluorescent protein expressed by your cells, you won't need to fix the cells. If you are going to be doing staining with antibodies, you will need to do a fixation/permeabilization step. I personally like to use one that involves 3.7% formaldehyde (in PBS) at 37C for 10 minutes followed by 100% of -20C Methanol for 30 minutes.
Chamber slides are indeed very handy...but you need to know which type of CSLM you have first. Is it an upright or an inverted?