First of all, Oxford isn't like a typical school--it's essentially what's called in America (at least) independent study. The way Oxford does it, there are optional lectures and mandatory weekly tutorials. At each tutorial, assignments are turned in and discussed, and new ones are handed out. If you read Psi's journal, this probably sounds quite familiar; this is because (IIRC) Cambridge was formed by ex-Oxford students about eight hundred years ago.
Oxford University is actually composed of a couple dozen "colleges"; these provide food, dorms, etc. for the students and run the tutorials. The University itself sets the curriculum, provides lectures, administers exams, and issues degrees.
The post above concerns a short message from Oxford explaining that my "college of preference" had been chosen. Normally, applicants provide a first and second choice for colleges; however, for students with no preference (or, like me, no knowledge to base choices on), it's possible to submit an "open application", where the University chooses the colleges. (I'm not sure how they choose, but I imagine it's at least semirandom.) The letter that arrived today said that the college of preference they had chosen was Lincoln College (which, incidentally, outdates the American President by a several centuries). It looks like a pretty good one--it's near the center of the city, and it has enough room to house all of its undergrads (apparently, some require students to find an apartment in the city for one or two years).