Shelltielover- Sorry if this is too long! I may have gotten carried away!
7 months old is a great time to start, even just for fun. Its a great way to bond with your dog. Make sure to keep your training sessons short and try not to be too repetative. Keep training to short periods, no more than five minutes on each thing, which could even be pushing it, depending on your dog.
Jumping through a hoop should be fine but watch the jump height. I think the rule of thumb for puppies is that they shouldn't be jumping as high as their front elbow so 10 inches may be too high.
Clicker training is a great way of teaching her how to hit contacts, if you're not already doing this. Its very simple, get a clicker and something for a contact (white is fine but yellow is prefferable. I use a yellow margarine lid). In one hand, hold the clicker behind the contact and see if you can get her to touch the contact with her nose. when she touches it, click and give her a treat. Do this each time she touches the contact with her nose. As she gets better at this, gradually move the contact closer to the ground until you can place it on the ground.
To help keep her interest try switching treats if she seems bored with them. I have about 4 different treats that I rotate between so that Sadie doesn't lose interest. I also try and train her close to meal times or I don't feed her till we get back from an agility lesson. If she's a bit hungry she'll be more interested in getting those treats.
Keeping the treats small is an important thing to remember too. If the treats are too big she'll get full faster and may gain weight, between getting treats and her regular meals.
One thing I use as a treat is cut up turkey hotdogs. I boil them and slice them as thinly as possible, then I cut each slice into quarters. I'll do this to a whole package, seperate them into plastic bags and then freeze them so they're ready when I need them. They last a long time.
Another product that I use I'm not sure is available in the United States. Its called Roll Over and its actually marketed as a semi moist dog food. No one I know actually uses it as dog food, just as treats for various dog sports and I've seen people using it as a treat at dog shows. Unlike hot dog, its very healthy. It comes in a large tube, I also dice this up into small pieces and freeze it. It lasts for months. Here is the web site:
http://www.rolloverpetfood.com/rolls.html
I don't know if your puppy likes to tug or not, but if your puppy has a tug toy tugging is also a great way of rewarding your puppy for doing something right. Since it can be a really fun game, its also a great way to strengthen your bond.