I have noticed that a lot of people who are beginning to use World Edit and people who have used World Edit for a long time have a hard time finding what a block ID is. Many people use just air or stone which works but for some blocks you need to know the Number ID. I found a website that shows each Block ID that helps with World Edit and anyone is free to use it! CLICK HERE!
or even easier hold f3 down then press h then hover over the block in ur inventory and it says the id and wtf syd u changed ur name?