So far I've watched the movie, and the pilot. I think it might be a little painful rewatching the first season. So much of the canon that is established in the beginning is later changed. Especially from the movie to the rest of the show (like how in the movie, Abydos was on the other side of the known *universe* and then in the first ep, well, the gate address stayed the same since it was the closest planet to Earth, also, even though it's in a different galaxy it has a 7 symbol gate address). I don't so much mind the differences between the show and the movie, but still, I think I'm going to be catching all the differences between the beginning of the show and what's established later on.
Like Carter's character especially feels really different from what she becomes later on. And also little things like how Chulak looks really different, and the people seem really different in the first season as compared to later seasons.