Welcome to Gaia! ::

So I know a dog who has a problem with jumping. She's not my dog but she does get brought over some times and she gets excited to the point where she jumps on you.
It wouldn't be a problem if she wasn't a German Sheppard with huge claws, paws, amount of body mass and as tall as I am when standing...

I want to train her to stop jumping on people but I'm not sure how. I know I'm not a professional dog trainer but I think it'd be easier to do it myself than shell out a bunch of money to actually hire a trainer.

Couldnt have said it better =)

Pushing a dog down tells the dog that you want to play, even though its not the message you are trying to send out. So all it does is make them jump more.

To get them to stop jumping when you go to feed them start hand feeding for a while instead of using a bowl. Do the above and when she has "4 on the floor" give her a handful of her kibble. She gets nothing when she's jumping, but when she's standing or sitting she gets food. Even the "dimmest" of dogs figure this out fairly quickly.
Once she's got it when you don't have the food dish start bringing it with you, but still hand feed her. But now you're putting it in the dish. To get them to stop this kind of behavior when something as good a dinner is on it's way can take time. So take it slow and if she gets really worked up when you reintroduce the bowl don't be afraid to take it "back to kindergarten" and start at the beginning and work back up to it.

I've had good luck teaching out young golden retriever pup not to jump by conditioning him to sit when he comes up to people - he doesn't get attention until he's sitting nicely and he doesn't get his food until he's sitting patiently, I put the bowl down and release him, of course for that you also have to teach a 'leave it' or 'wait' command until they know the drill.

I had the same problem with my dog =u=

I've gotten hit in the face a couple of times because of her jumping so high.
I tired turning my back when she is all hyper and jumping, it seemed to work for a few seconds but then she starts to hump me... =u= When turning my back didn't work I gave her a firm "NO" command. That would work only sometimes. I found out that leaving the area when she is acting up and coming back works well. Although I would repeat the action a couple of times until she is calm.