I went to pick her up yesterday and noticed her eyes seemed a little gray, so I figured she's probably about to shed. However, I wanted to handle her to see if the mites were gone and she very oddly curled up into a tight ball and almost made a (?)hissing(?) noise.
Like someone said, she's probably in shed. You can still handle her, but most(including myself) like to leave them alone until they are done with this process.

I obviously got a little scared and just as I was about to put her in my hand, she twitched a little. I thought she was about to bite so I set her back down quickly (I didn't drop her).
You don't want to get into the habit of putting her down every time she hisses, granted she might be shedding. If you put her down every time she hisses, then she knows that's all she has to do to get you to leave her alone and then you'll never be able to handle her without her hissing or threatning to bite. Like someone said, getting bit kinda comes along with the territory.
I'm a very anal and paranoid person though and I'm worried that the sudden movement of putting her back down might have scared her. I know that dropping a snake can be very traumatic and they loose trust in you. Today when I went to pick her up again, she curled up into a very tight ball which is not like her. I'm thinking maybe she is about to shed and just wants to be left alone but the sound she made yesterday threw me off quite a bit.
She'll be fine. They are called Ball Pythons for a reason. Lol. My first one used to curl into a ball all the time, but after a few weeks are consistent handling he is great and doesn't do it anymore.

So, I'm basically just unsure as to what to do with her for the next few days and whether or not to leave her alone. If she is in the process of shedding, I don't want to pick her up and soak her if she's going to react the way she did. At what point in the shedding process should I be soaking her anyway?
Soaking is only nessecary during the shedding process if the animal has stuck shed. Let her shed on her own. Just bump the humidity up to abot 70 or so if you haven't already

Also, I'm hoping somebody can tell me if her behavior is normal. She spends quite a bit of time in her hide and I want her to move around her tank a bit more. Obviously I know this comes with time but I'm just thrown back by her not letting me handle her.
They are most active at night and spend most of their time in their hides during the day, so it's completely normal. I usually don't see mine during the day unless I take them out for a handling session..

I was also planning on feeding her on Monday, but now I'm not so sure.
Looking forward to replies =]
She should be fine for you to feed her.