Is a 30-06 good for deer hunting?

Yes.

This is one of the most popular calibers to hunt deer with.

I know a lot of folks that go as low as .243 to hunt deer, with a larger grain bullet this caliber can be affective as it is moving with a very fast velocity.

30-06 is a good medium caliber bullet that usually moves pretty fast, it is also an adopted military round from back in the day so the selection on ammo is pretty diverse because of it's popularity.

For a great long distance round I heard that the 300 Winchester mag is very affective.

Hope this helps.