Douglas is one of Cork's nicer, and best-served suburbs. I'd classify it as part of Cork City, not County Cork as it's part of the continuous built-up area.
It is a suburban village with loads of restaurants, bars, shops etc has two large shopping centres which include a rake of small shops, boutiques, etc as well as a large Dunnes Stores, Tesco Extra and M&S.
It also has UPC broadband and Eircom Fibre optic broadband (just being rolled out) in most locations.
In a Dublin context, I'd compare it to say Dundrum or something like that.
There's quite a bit of accommodation around that area, but not much of it would be student-oriented as it's not in a university area. It's mostly suburban houses but, there are some apartment complexes around too.
As areas in Cork go, it's also one of the most expensive in terms of accommodation, but it does literally have everything at your doorstep.
Your best bet for rental prices, is to check www.daft.ie
to get an idea what's out there.
Also, check your bus routes carefully. The routes to Ringaskiddy all go through the centre of Douglas Village and along the Douglas Road from the City Centre.
Douglas covers quite a large area of the south of Cork City and there are plenty of areas of it that are a good 20 minute walk to the village centre, so you just make sure you're actually on the bus route you need to be on.