Is it important to watch the movie in sequence, or should I watch it after the series? Does it spoil later on shit?
I also "bought" Turn A Gundam. At the Internet "store." With "money."
If you watch it before the series, it'll spoil tons of shit. You can just do what MAF said and watch the series and skip the movie...the movie's basically there for two reasons: One, the original series director died and there was a big gap between release of episodes, so they needed some material to fill in the gap so folks wouldn't lose interest (the movie also recaps stuff from previous episodes), and two, it explains how the protagonist gets from point A to point B at a certain part in the show.
Turn A hasn't been released in the US, so the fansub route is okay (that's what I did).