Um, as far as slides go, there is a specific kind that some will use called a McMaster slide. This has a grid that can be used for egg counting, but I saw that when my vet and another one did a count they just used a regular slide with a glass cover slip to see how many and what type of bugs were in there.
As far as the microscope, I am not sure of a specific web site but I do know that it doesn't have to be a high end one.