Start here:

http://www.flyertalk.com/glossary/

CO is the IATA code for Continental Airlines. You can puzzle out most of these from context, for example: AA, BA, CO, DL, UA, and US. But some need to be memorized: WN = Southwest Airlines.

"W" (in this context) is a specific fare bucket. Commercial aircraft have only a few cabins (economy, premium economy, business, first), but airlines publish multiple fares in each cabin with varying restrictions and prices.