So I was riding today on my newly adjusted bike (shifts like a dream again-- Thanks everybody!) and I was about 50 yards from my front door when I get a flat rear tire.

• So what do I need to order (just tire, or tube also?) and what size? And from where (assume no local bike shops)?
• Also what tools would I need to change the tire (I'm assuming parktool.com has a how-to, but if not please point me in the right direction)?
• The last thing I want to have to worry about on a long ride is catching a flat in the middle of it (and I don't like carrying extra stuff with me if I don't have to), so what would you folks suggest for the most DURABLE road tire? I'm on pavement 100% of the time, with the occasional rough spot or random rocks. Also I'm in this for exercise, not speed so if it's not the fastest tire in the world I won't be upset.
• Let's say this happens again-- What should I carry with me on a ride to change it on the side of the road? (remember, I'm a minimalist as far as equipment)

Thanks a lot everyone, I'm looking forward to learning yet another invaluable skill related to cycling!