If you want a solid foundation, the best piece of advice I can give you is study your b0ll0cks off @ uni (boring but true). Get a copy of the reading lists for your courses and pick them up (2nd hand if you can; they should be pretty easy to get your hands on, there are a few textbooks that are used in most business schools. Try Amazon). The courses and material are unlikely to teach you
how to trade, but performing well in them will certainly help you on your path to
becoming a trader. I speak from experience; the route to trading professionally is far more convoluted if you spend ALL of your time playing rugby, drinking beer and chasing women
As for trading, there are plenty of resources here on T2W about taking the first step. I would play with a simulator over the summer; get an experience of the various products out there (Indices; Interest rate derivs; forex; equities etc...) and see which you like the best. Personally, I would suggest forex if you're going to be a student. Indices et al tend to have more "compact" trading days, perhaps with liquidity only available during the products native session. If you are a student, it will be very difficult to allocate enough time in each day for trading around all of you other student activities (see above

) forex, as a general rule, is a "slower" market to trade. Added to that, with some brokers (e.g.
OandA), you can place custom trade sizes as opposed to contract specification. If you want to trade w. 500quid, a tick size of $12.50 is leaving you horrendously over-leveraged. And I wouldn't recommend trading with the 500quid anyway; no offence mate, but it is likely that you will lose it. Waste it on food and rent etc...
As a start, "financial Markets" by Kieth Pilbeam is a good introduction to the markets as a whole. Nothing too specific, but it should put you ahead of your classmates come septmeber.
FYI BBG and Reuters are available for trading to instituitions only; your uni will probably only have access to the data they provide for research, and poss. for 3rd yr students to get experience with, as sweetners to their CV's.