Owning a bicycle is a good idea, but taking care of it yearns for an experts’ piece of mind. You should not worry too much about taking your bicycle to a mechanic when you can handle the repairing on your own. It will rather save you the cost of every moment you get into a problem. Grab a pick of one of the toolkits from the above review. I assure you that, absolutely no day will you seek a mechanic for service.
If you have just a short time in Seattle there is only one way to see the city. Walk at 2.5 miles an hour? I don't think so. Take buses and trams that you have to wait for and that might not even get you where you need to go? No way Jose. Drive your car? Hahahaha get outta here, don't even talk to me. But what about a BICYCLE??? Now that's the ticket.
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.