Debatepedia defines itself as “the Wikipedia of debate and deliberation”. It’s a useful as a source of arguments for classroom debates on everything from Advertising to Zoos. I think you guys might find this site useful in learning the ways to construct an argument. You’ll quickly learn that there are some standard strategies for doing this.
You may also want to have a look at Debatepedia’s global warming solutions series with the UN Foundation here. We (at Debatepedia) just finished creating it, and we’re very excited about it. Best,