Here is a link to pictures of my tomato's. I was wondering if the brown
leafs are normal or if I am doing something wrong.

I agree with HomerS. I get some of this every year.
If it were my garden, I wouldn't be concerned right now.

That's my experience too. Usually I scratch my head, wonder what is
going on, maybe water a bit (if I haven't been), and basically ignore
it.

Can't promise that always works, or even is the best approach, but it
has worked for me.