Sorry for my absence, now I need your help!

Woooowwww... I can't believe I haven't posted in almost 2 weeks!
Like I said before, there's just not much going on this summer.
I'm currently at home in Dallas for a visit and a friend's wedding and dropping the dog off. Yes, sad. Ms. Elle Woods will be living with he grandparents for the next three months!

Why three months? Because in less than a month I am leaving on my European adventure!!
Now I need your help, dear readers!

For those of you who are new readers or don't remember - I am studying abroad through my law school in Europe for 4+ weeks in July and August.
We are staying in Prague, but am going to Dublin first, and plan on taking several other trips throughout our time there.
I am living in a house with 2 girls and 6 guys (all friend from school), which should be totally hilarious and so much fun.

I am the only one in the group who has never been to Europe before, so I have lots of experts with me, but I feel like I'm already annoying everyone asking a gazillion questions.

So - here's where you guys come in!
First off - Let's face it: What to pack, what not to pack. I'm semi freaking outtttt about fitting my life into a suitcase for over a month. I'm actually probably going to bring 2 suitcases and a backpack. Is this ridiculously too much? I just don't see myself being able to fit everything into 1 suitcase.
How many pairs of shoes do I need to bring? What kinds? I know flats and tennis shoes that are comfortable for walking, but what else?
The other girl that I am living with and I have decided to go in and split toiletries that we can share (i.e. only bringing one tube of toothpaste, sharing a face wash, buying a hair dryer when we get there, etc.)

Second - What sort of "gear" do I need? My cousin is telling me that I need to get some sort of a rain coat and a backpack that is bigger than a regular backpack for our weekend trips. But really? I just don't see myself wearing one of those ridiculous tourist backpacks.

Next - where should I go?!?! This is the most exciting part! We will (hopefully) be traveling every weekend. If not every weekend then at least 2 or 3 of them.
The problem with this is that everyone in my group has been to Europe before (some of them have been 3+ times!), so they've all done the typical Paris/London/Rome tour. This is why we're going to Dublin before. Having never been to Europe before, what is one city/country that you guys would say I definitely HAVE to visit? I can probably convince someone to go somewhere they've already been before with me for just one weekend, so I want to make it count!!

Sidenote: I am so thankful that I got my ticket booked on AMERICAN AIRLINES! Yay!
I am so not a nervous flyer AT ALL, but for my first trans-atlantic trip I want to be totally comfortable and since I fly American all the time, this will be perfect. I already reserved my aisle seats and I'm super excited to be racking up the frequent flier miles!


So hit me with your advice, I need it!