For the ones arriving in Sheffield, this is some advice on where to find the basics (food and home appliances). It's very easy, actually because there's one street where you can find everything you can possibly think of - and very cheap. It's called The Moor. I know for sure that buses 40, 94 and 95 go there, but there are certainly others because it's a very popular street.
By the way, regarding bus tickets, there are two main bus companies in Sheffield: First and StageCoach. StageCoach is cheaper if you buy single tickets (they have a special student discount - £0.50), but for a bus pass First is better. The cheapest one I found was the week pass (£5). It gives you unlimited rides in the line you choose. The line (named as colours) covers certain regions of the city. Usually one line will be more than enough to get around.
But back to The Moor, you just have to ask the driver to let you know where to get off. The bus stop is just in front of it, and as you go down the street you'll see a big round-shaped sign with "The Moor" written on it. There, in the middle of the street there are vendors selling cheap socks, scarfs, suitcases, etc. If you go down, on your left-hand side you'll see Poundland where everything costs... one pound! And they have a huge variety of things, from food (processed, no groceries) to home appliances, cosmetics, etc. For more home appliances, walk to the end of the street and on your left you'll see Home Bargains.
As for groceries, there's a big supermarket (Sainsbury). For the ones who are not great chefs (like myself!), a good tip for cheap frozen food is something Fulton Frozen Foods. It's on your right-hand side as you're going down the street, before Home Bargains. There you can find not only frozen food but also meat and great, cheap yoghurt. As for the rest, just look around. There are heaps of shops selling everything!
Finally, if you guys need a new SIM card or mobile phone, the place to go is Carphone Warehouse. It's on High Street, the main street in the city centre. They have their own network, called Mobile World. If you buy a Mobile World SIM card, you can make cheap calls abroad - by cheap I mean cheaper than calls to the UK! The only problem is that their signal is not as strong as other networks', but it's certainly worth it to call home.
I hope this helps. If anyone has any questions about Sheffield, I'll be happy to help! I'll be looking forward to hearing from you guys who spent a semester in the other cities of the consortium.