For humanities the first year doesn't really exist. I know girls who, in all seriousness, were probably drunk/hungover more than they were sober over the course of the whole year, and they eased to 2:2s in the first and second year. I got a mid 2:2 in Law in my first year and University as an academic concept hadn't even occured to me. I went to see Dirty Pretty Things the night before one exam, got pissed, the last train from Middlesbrough to Durham was cancelled and I had to get a bus back which didn't get in till about 3am, for a 9am exam. I was late for one exam because I was playing Pro Evo. One exam I'd only went to two lectures in all year. Last year I did some revision and I got 59/a high 2:2, but completely ****ed one exam up by wrongly assuming there were only three questions to answer (so only revising three topics) when there were four. So I'll just step it up a gear and *fingers crossed* should coast to a 2:1. But the thing is, with humanities, especially law (arrogantly assuming law is more difficult than other humanities) you could work your arse off, and be really intelligent, but still not get a first. So, my logic is, do pretty much nothing, or as little as you can to get a 2:1. You can gauge this in your first year. All of my friends are humanities people and some did loads of work, and some did practically none at all. They all got 2:1s. Granted, the ones who did loads got high 2:1s, and the ones who did little got low 2:1s, but does it really matter?
For sciences, you're pretty much ****ed on the 'doing as little work as possible' side. But on the plus side, if you do work hard and put the effort in a first is very much attainable.
Moral of the story is: test yourself out on your first year. Anyone at Durham is at least marginally intelligent (though once you're here you may begin to question that), so you can ratio out your first year score to effort, and work out how much more/less you can do in your second and third years to get whatever grade. General rule = humanities easier to pass, harder to bitchslap. Sciences harder to pass, easier to bend over.