In about a year, on Aug 21, 2017 there is an eclipse of the sun in the US from Oregon to South Carolina. It is the first one in many years for the US. To view it, I plan to go to Eastern Oregon where the weather is likely to be good. See eclipse2017.org and eclipse2017.nasa.gov for the exact path and more details.
How long does an eclipse last (if you are not moving)? Here is a quick "back of the envelope" calculation: since the sun and the moon both subtend an angle of about 0.5 degree (they have to be approximately the same or the moon would never eclipse the sun so perfectly), and the earth rotates 360 degrees in 24 hours, it means that the time period to go over 0.5 degree is about 2 minutes. This is a rough approximation since the sun and moon are both circular disks; it is the time for the center of the moon to pass over the sun. The time from the leading edge of the moon starting to hide the sun to its trailing edge leaving it will be about twice that. There are partial eclipses at both ends, and even less if you're away from the path of totality. See the NASA site for more precise numbers.
Another good "rule of thumb" (literally) is that your thumb at arm's length subtends about 2 degrees. So for example, you can verify that the moon is not really bigger when close to the horizon. No matter where it is in the sky it will be about 0.5 degrees, and your thumb can hide the widths of 4 moons behind it. But don't do this with the sun! Never look at the sun directly.