Amazing!
Do you know where you will be living?
I was there for 6 months and had a fantastic time. Can't really think what to write now though.
Shopping- all the main Western Shops are there so no probs.
DVDs I have no idea where to buy legal ones But don't bother with getting them from teh street sellers as they mostly lie about them having english subtitles. However, at the huge craft and tat market at Izmailovsky there are some very good sellers.
Food- Find your local market and watch the locals. I lived out at Planernaya (top end of the purple line) and we had a huge market with rows of kiosks but there was only one bread place that had a queue at delivery time. Also found the market a great place as much cheaper that supermarket and good for practice. Shopped around a bit at first but soon realised which of the babushkas overcharged the English girl and which ones took me in hand, laughed at my Russian, patiently reminded me of vegetable vocab etc.
There is a very posh Supermarket on Tveskaya in the centre where you can find non-Russian stuff and all the European stuff you miss.
Getting around on the metro is quick, easy and cheap.
They love coffee and cake places Actually asking for hot chocolate gets you a cup of thick, molten chocolate. For a hot chocolate ask for cocoa.
You need a spravka to go swimming that says that you don't have all manner of skin diseases and STIs. You have to chat up the right people for this, the offical way is to have blood tests etc, the unoffical is to pay, see a dermatologist who will glance at your skin and collect your certificate.
Erm....basically it is crazy and you must embrace that. Nothing works when you want it to, phone lines are often shared which can be interesting, hot water and heating is all centralised so while you never run out (bliss), if they decide to do work on your bit you can find yourself with no water at all just randomly (not so much fun). But so long as you relax, take it all in stride and accept that there will be days that infuriate you then you'll be fine.
Oh and don't be one of those bloody expats who doesn't even learn the alphabet and goes round clling restaurants pestopahs because that is what the letters look like.