Anja,
I chose this Agility group as they are affiliated with the training school (
www.kurse-fuer-hunde.ch) I attend - which I chose because they are right in the neighborhood. Which is a good thing, as my Hooligan is... well... a hooligan

, meaning we need to spend a LOT of time in training activities.
Seriously... my girl is a very challenging dog. And, she's a lot smarter than I am.

I really have to be on my toes at all times to channel those overactive brain cells towards constructive activity. I've been very lucky to stumble on to this training school, the trainers have been such a fantastic support to me.
(Some of my other dog have had difficulties to overcome, I'm no stranger to dogs with behavioral issues - but the Hooligan knocked me for six. She has made me re-think everything I ever thought I knew about dogs, dog psychology, about motivation, about training. It's been in interesting learning curve, to say the least.)
Almost three years on, we are starting to see the light at the end of the tunnel (knock wood), and it really is thanks to the Hundeschule that we have come this far.
We do Familienhund training, which is sort of a bit of everything - advanced obedience, a little mobility, a little search/tracking, a little introductory work on the agility obstacles - and theory discussions as well. It's a pretty laid-back atmosphere - as the name suggests this is designed to help your teach your dog to be a good 'family dog'. The groups are small, and there is no pressure - it's positive, reward-based activity - and plenty of support.
I got into Agility ages ago in the States (again, for fun, not competition) with my first sheltie. The perfect combination of physical exercise and mental work out - we had such fun together.
So... I thought that Agility would be a good thing for the Hooligan (also a sheltie) as well. We started with a beginner's class, just three other dogs. Again, low keyed, work at our own pace, really enjoyed it. My girl needs to work off that excess energy, she needs to be thinking, planning, figuring things out. And then we moved up to the next level...
... where it all went pear-shaped. The Hooligan is a highly reactive dog - and the hyper-charged atmosphere of 'real' Agility has the potential to send her into the red zone. Which is why I've started with the CU program. I don't want to give up on agility yet, as she absolutely loves running the parcours. But I'm not sure that Agility - at least in that setting - will be the thing for her in the long run. I need to figure out a way to give her the fun, exercise, and mental challenge of the activity, within a calmer atmosphere. Perhaps we'll just keep doing the beginner's course over and over, if the Agility trainer will let me.
Agility is a fantastic sport for many dogs - if your dog is high energy, loves running, jumping, thinking - and isn't bothered by the excitement - it should be right up your alley. Start with a beginner's class - the only preparation you really need is good basic obedience work, a solid recall, and the ability to work off lead. You will learn everything else in class.
Go visit a few classes, talk to the trainers, see if you feel comfortable. Different trainers take different approaches - make sure you choose one right for you and your dog. By the way 'Plausch' Agility is generally a group training for fun, 'Wettkampf' groups train seriously for competition.
Very important: Your dog should be at least 12 months, and preferably over 18 months old.(Breed/size dependent.) If in any doubt, ask your vet if the activity is OK for your dog. All the jumping and tight cornering could damage immature bones, which is why it is recommended to wait. Some groups offer special puppy or young dog classes, though, without jumping or where movements are restricted.
Oh - and you'll be doing a lot of running as well. I'm a lot older, slower and rounder

now than I was the first time I did Agility... and boy, do I feel it.
If your dog likes doing tricks, what about Team Training (heel work, dog dancing, call it what you will...)? When I first heard about this I thought: Dancing? WTF? How silly is that?

But guess what - we tried it, and love it.
Team training has been a godsend for the Hooligan. It's is basically doing heel work/ co-ordinated steps/ tricks with the owner. You work close together, the dog has to focus on you, stay with you, ignore what is going on in the background, has to think carefully about what you are asking. It is slower, more controlled. It has really helped me to read my dog's body language better, helped us to communicate better, helped her to develop her self-control - and for the Hooligan it's the perfect 'cool down' antidote to the excitement of Agility. (I do a Team Training class at the Hundeschule.)
Whatever sport or activity you choose, the point is to have fun together, to further develop the bond between you and your dog.
Good luck!
(By the way - I luuuuuuuurve Huskies. Is that her in your avatar?)