Hello guys,

Make sure your phone is unlocked and at least tri-bands.
There are few 4, mobile phoine companies,  Activ (K-Cell) and Beeline are the most popular one. Can get PAYG Sims from supermarkets and can top up at kiosks (with tax deduction), notes only. There are mobile phone shops where you can get the micro sim as well as other mobile bits. Don't expect everyone  can speak English. If you are working for a company/school, they can sort this out for you apart from other paperwork matters. There will be a lot of paperwork (to deal with) here.

안녕!! Welcome to Astana!

  Firstly, don't be afraid of the weather. our climate is not wet and muggy as in Korea so the winter here is not so cold in the comparison with winter in Taehanminguk! Quite bearable. I know because ive been to Korea last year. Believe me winter in Korea was really cold even for me. You should just take with you warm clothes.
Secondly, as Jaming said you can bye sim card (Active/Beeline) in mobile phone centers. And you can supply ur mobile phone everywhere, even in small shops.
  Thirdly, if you are an exchange student or a worker don't worry. There are Koreans in here, mostly russian lang learning students and also 한국 문화원. You can find a lot of Koreans and korean lang learning students over there.
You can find also quite amount of entertainment places. But comparatively with Seoul and Busan Astana is really small, anyway its a young capital with only 20 years history. Exept for the young generation and students people here don't speak english.So for adaption in the beginning learn some russian basic phrases (how to ask a road, or buy food).
p.s. after arriving contact me, i would be glad help you.
화이팅!!!