The flight will arrive in Taipei at seven tonight.
Tonight the flight will arrive in Taipei at seven.
Both sentences are correct except the use of "to". It doesn't matter where you place "tonight". The difference is just when you place "tonight" in the front of the sentence, you emphasize it more, because you want people to notice right away without even knowing what might happen tonight.
As far as using preposition with arrive is concerned:
you can say:
It was late by the time they arrive at their hotel. The President Lee arrived in Tokyo today.
The train arrives at the station on time (The train arrives on time).
2012-09-09 12:22:28 補充：
By the way, "Tonight the flight will arrive in Taipei at seven" is better to write as
Tonight, the flight will arrive in Taipei at seven.
2012-09-09 13:52:08 補充：
When people read the above sentence, the first impression is "tonight", people know whatever is going to describe will happen tonight.
When you place "tonight" at the end, people will know the event first, then the time it will happen.
2012-09-09 14:15:29 補充：
"arrive" itself already implies "to", therefore, using another "to" after "arrive" is kind of redundant and awkward. It is better to use preposition "at" or "in" to describe how "arrive" relates to the the location.
2012-09-09 14:17:38 補充：
"I arrive at hotel", it describes "I" am at the hotel. I can be outside the hotel entrance, or inside the hotel.
2012-09-09 14:20:51 補充：
"I arrive in Taipei". It describes "I" am INSIDE Taipei no matter what. After all, you cannot be at border of Taipei city and say "I arrive in Taipei". Once I step INSIDE Taipei city, then I can say "I arrive IN Taipei".
2012-09-10 00:03:35 補充：
Master Louis! Your examples for using "arrive" is nicely demonstrated. Especially, the first TWO examples are quite useful. In the past, I saw people use "小地方" or "大地點" to explain why use "at" or "in" with arrive.
2012-09-10 00:06:00 補充：
I don't quite agree with it, after all "小地方" or "大地點" is too subjective. a person's "小地方" might be a "大地點" for the other. Then we will trouble to determine whether to use "at" or "in".
2012-09-10 00:06:45 補充：
will trouble ... ==> will have trouble ...