The weave pole guides work pretty well, I have a friend who swears by them and her dogs are amazing weavers. I have trained both of my dogs with the weave-o-matic and that works nicely, too. I did try backchaining with a rescue dog, and it was effective, too. The only problem I have found with backchaining is that it teaches the dog that it is possible to do an entry somewhere in the middle instead of at the very first pole. In practice it might be perfect, but on the course, the dog may forget a good entry in the excitement and jump in at the middle. The less opportunity you give the dog to do something "wrong" with the weaves, like an incorrect entry, the better.
If you are just doing it for fun, not to compete, then just do whatever you are most comfortable with!