well, this varies from place to place. i sat the IELTS exam on 11th July and i was extremely disappointed to see the quality of service british council south africa provides. they didn't provide any headphones. it was a huge hall and they used big speakers. it was a freezing morning on 11th July (its winter in south africa these days, opposite weather as compared to other countries) and there wasn't any heating system. infact, when i got there, they said they will start with reading and writing first because they dont have any power. after we did the reading and writing, they took us to an adjacent building where there was power and then we did listening test there. no comfortable chairs and tables. very disappoiting service. but just like i said, their service could vary from place to place. i think i did satisfactory though in my ielts. but waiting for 24th july to get to know of the bands awarded. ielts classes are not required. just like aanbaan advised, download the books and do a few sample tests. that should be enough. if you are applying as a skilled worker (means you are skilled enough to apply as a skilled worker), you shouldn't have any problem cracking ielts in just a week time.
good luck with your ielts.