Great Dress at Target; Hair Care Woes

I had a really good trip to Target this weekend.  I still haven't found a maxi dress that I can wear--apparently, big boobs and hips indicate that you are tall, very tall, so I haven't found one that doesn't drag on the floor. I did find this chambray dress though, and I fell in love with it--1. the fact that I fit in to a dress from target that was not in the plus or maternity section, and 2. it really is super cute!  Just look:

I also bought these sandals:

I bought some fitted tees and workout clothes as well.  I've been feeling pretty good about the way I look lately, and I enjoyed shopping.  I'm not skinny by any means, but I am more toned than I've been in a long time.  I'm enjoying wearing clothes that make me feel like I look good.

If only I could do something about my hair.  I had the straightest of straight hair up until a few years ago.  I never used a hair dryer, never had to worry about it.  Now?  The shit is straight up wavy/borderline curly.  If it is humid, as summer in Buffalo tends to be? Forget it.  What is a girl to do? It seems like even if I blow it straight complete with product, that as soon as it hits the humidity, or I sweat a little bit that it all goes to hell.  Being that I never learned how to do my hair, I am at a loss.  So tell me--what am I supposed to do with my hair?