a few questions about rims' measurements

[Bartizek]

If a measurement says 17x7 or 17x8, I'm guessing that's how wide the rim itself is? am i right?

and if that's the case, which is better?

Also what offset is best for the celica?

[redlinee46s3]

17 is the diameter (height) of the rim and the 7 and 8 are the inside width. The wider the rim the wider the tire you can use. Width is up to your personal preference. A good offset for a 17x8 wheel is +35.