Bitrate help!

[liammews]

So I hear alot about bitrate but I'm failing to understand it.
I own a Canon 60d and want to know what the best 'bitrate' to use is or the best settings to use in the 'bitrate' menu. What advantages will I gain altering the bitrate and if any, what are the disadvantages.
Thank you for your help in advance!

[dmilligan]

http://en.wikipedia.org/wiki/Bit_rate#Multimedia_encoding
http://en.wikipedia.org/wiki/Lossy_data_compression