I did the channel method with my boys. There are lots of good videos out there that show progress with a 2x2, which seems to be the preferred method by most trainers. I did the channel simply because I didn't have to buy any equipment lol. I think both methods are great and they can be used in conjunction with each other. One of the benefits to the channel is they get a really nice, fast rhythm right from the start. The advantage to the 2x2 is a solid understanding of the correct entry right from the start. Don't be worried about screwing him up, weave poles are tough to teach, it will take time, it's one of those things you have to play with (very two steps forward one step back.) just make sure you teach him to enter on his left and you'll be fine
Odin ~ GSD
Zuri ~ German Coolie
Havoc ~ (aka "Super") GSD - Rest easy buddy.
Keeper ~ (rest in peace little stinker) (Aussie)