You are advised not to use your UK sim card in Russia, as you will find it very expensive, even to phone within Russia. On arrival in Russia, you can buy a pay as you go sim card very cheaply. You will need your passport, so do this straight away before handing in your passport for registration, as you may be without your passport for some time. Before leaving the UK, make sure your phone is unlocked. It can be unlocked in Russia, but it will cost a lot more.
If you take your laptop with you, some homestays may have a wi fi connection. However, this cannot be guaranteed. Alternatively, you can buy a dongle to get access to the internet. Many cafes have free wi-fi. Some of the RLUS centres will have computers with free access to the internet. There are also a number of internet cafes, but they can be expensive if you use them regularly. There are further details in the briefing documents for each centre.
RLUS has been using Telediscount for some time. To phone a landline in Russia, dial 0844 462 95 95 and follow the instructions. You will be charged 2p per minute. To phone a mobile, dial 0844 566 43 43. You will be charged 5p per minute. You pay nothing upfront. The costs will appear on your next bill. Be careful phoning mobiles, as you will be charged in Russia for receiving calls.
Alternatively you can go to the "Phoning Russia" link on the left.This will have list of other providers.