For our microbiology class, I don't remember if it was a lab final or just a lab assignment, we had to figure out an unknown. However, the information for how to do this was in our book, in our lab book, and in a handout that the teacher gave us.
In other words, in the lab manual there were many assignments on different types of tests. They started from general, like the gram stain to figure out if you've got a gram negative or gram positive organism. Then you did some more testing- like the 3 different tests that turn yellow with glucose metabolism, and so on. I can't remember them all. We had a lab that we did that was full of just practicing the tests, and then started on our unknowns. We got a test tube, numbered, (the teacher had a list of the numbers and what organism was supposed to be in the tube for her reference), and set up the required number of tests, labeling each tube so we'd know what test it was, and stuffed it in an incubator for 48 hours.
Two days later we had to go over each test tube and write down our results in detail, and then use the material to figure out what organism it was. Now, the reason I'm saying all this is, that if you know what your unknown IS, then you should have done a battery of tests to figure it out. So, making a flowchart of what you did shouldn't be that difficult:
Gram stain positive or Gram stain negative
If positive, what test is next? If negative, what's next?
....with little boxes around the items, and lines between them. There should be examples in your microbiology book. But if you're creating a flowchart then it should be a record of what YOU did, not copied out of the book.
This assignment is a lot of fun and it looks at lots of things: your understanding of the material, exactness of your method, ability to interpret results, and ability to report your results. Good luck with your flowchart!