Lupus can present in thousands of different ways, so unfortunately there is no such thing as a "cut and dry" case. The good thing is that rheumatologists are aware of the complexities of diagnosing Lupus, so they often start treatment immediately and use how you respond to specific treatments as part of the diagnosing process. (Also good that the GP knows enough to know he's not the expert at diagnosing or treating Lupus.)
Since you've read Lupus 101, you've seen the list of symptoms generally used for diagnosis. Take with you to the rheumy appointment a bullet-ed list of symptoms you've had, both things on that list plus anything else out of the ordinary. Include when you had the symptom and how long it lasted. Anything in the last 10 years is fair game!
Don't worry about
not getting a diagnosis at the first appointment. Like I said, many rheumies try some treatments first before confirming a dx. Expect something like Plaquenil (a disease-inhibiting med) or Prednisone (to control inflammation). Or the rheumy might take lots of blood and see you again in a few weeks.
Meanwhile, try to make sure you drink enough water, eat protein & veggies, and get deep restorative sleep! These things always help us heal and feel better. Let us know how it goes!
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2000DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde