I have a few questions with regards to Oystercards:

1. Is there a good website or hardcopy leaflet that explains
Oystercards in a clear fashion? I've been reading some of the threads
in this group, as well as the official TfL stuff, but I'm still
confused as to precisely how to purchase, maintain and use one. I
haven't needed one yet, since I don't use the Underground regularly,
but that may change in the future and I don't want to be futzing
around with it during peak periods, incurring the wrath of everyone
behind me ;-)

2. I am a full-time university student, and when I discovered that I
could get ahold of a Student Photocard and use that to get discounts,
I acquired one. The problem is, I don't know how to use it! Is there a
place where I can read about how to use a Student Photocard? (This one
is the green variety with the "Student" label and it has an XA prefix,
if that means anything).