
Good plan! I used to do agility with Remy (can't afford it right now :( ), and he taught me one thing - basic obedience makes all the difference!
A particularly important thing IMO is the recall - your dog must come to you when you call him, not when he wants, this i remy's main issue at agility - he used to do an obstacle then run off to eat horse poo

His stay could use some work as well...
Make sure you check out a club
before you join it - I've been to three now, and they each had methods that riled me. I left the first because the trainer pinned and violently shook a little collie because he got in the way of a fight and got nipped (no damage done), then did it again because she growled at him; the second club taught the a-frame (at full height, even for a beginner dog) by having a person either side of the dog with a lead each, taking a run-up and hauling the dog over the top - scared the heck out of Remy - and the third insisted (in the beginner's class) that you should shout your command to the dog and give it no choice at all about doing it. Not my cup of tea!
I don't mean to scare you, I just want you to be aware that some trainers do have less than pleasant methods of doing things, so do check them out first. It's a great thing for dogs that like to move - suits Remy perfectly, he has constant motion issues, can't stand still for long :D Good luck, I'm sure you'll find a nice club and have a great time doing it - I'm going to start Opi on agility soon, she loves it!