if you change the left side, bottom dates on the forum page, you can go back and see the other threads on thanksgiving crowds.
that is what i use to put up links to answer questions from newbies usually.
on to your question:
the days prior to Tday are not bad at all.
Turkey day will have it's crowds and major crowds for the days after.
so many take advantage of the period their kids are out of school and do the parks.
if you are staying on site at universal, the fotl perk will help alleviate the long waits in line for rides and attractions.
if you are going Tday and after, and staying off site, be at the park very early prior to opening.
you will get a lot done until the crowds start growing around 11ish each day.