Can someone give me a brief synopsis of buying a ticket from the vending machines? Are there buttons you push for the zones you'll be traveling through? Also, how would I purchase a ticket from a station manager without sounding like a total idiot? Would I simply say, "One ticket for zones 1-6?" Thanks a lot.

You're stressing too much. Yes, that would be fine with what to ask an attendant. There are a couple of kinds of machines and while it's hard to explain here, trust me, they are very easy to follow the directions for. On some of them you don't even use a zone, you enter the station (by scrolling) that you want to go to, and the correct amount to insert will come up. You put your money in and you get your ticket out.

You can also use your credit card in the machines. We did make a mistake, went to the ticket booth and the person was VERY helpful and solved our problem. We found all the 'tube' employees to be great boosters for London.

You need to specify which type of ticket you want. Basically, you can buy a "single" (one-way) for just one journey or a "Travelcard" which allows unlimited travel within specified zones - these can be for one day or for periods of up to a year (for more than a week, it will be in the form of a plastic Oystercard). All stations have ticket offices but opening hours vary and there can be long queues at busy stations.

http://www.tfl.gov.uk/tfl/ftt_tic_intro.shtml

http://www.tfl.gov.uk/tube/tourists/?lang=en

By the way, while sometimes it may be a bit difficult to understand Brits through their accent, I'll say this. I've never had a problem understanding everything any tube attendant has told me. In New York, I've NEVER understood anything a single subway attendant has spoken to me.