2-way switches.
#1
#2

If you want 2 switches to control the lites, that is called 3-way switches. Simply follow the wiring schematic provided with the switches, which will power the first lite. You will need 2 3-way switches. To power additional fixtures, just run a 14-2 wire from one to the next, to the next.
#3

hello BigR,
what u r wanting to do is called 3 way switched. here r 2 links to sites that explain how 3 ways work, if u have further ? feel free to come back or email me http://www.howstuffworks.com/three-way.htm
http://www.wfu.edu/~matthews/courses/p230/switches.html
what u r wanting to do is called 3 way switched. here r 2 links to sites that explain how 3 ways work, if u have further ? feel free to come back or email me http://www.howstuffworks.com/three-way.htm
http://www.wfu.edu/~matthews/courses/p230/switches.html